diff --git a/.changes/missing-production-runtime-variables-in-preview.md b/.changes/missing-production-runtime-variables-in-preview.md
new file mode 100644
index 0000000000..acda6f98fb
--- /dev/null
+++ b/.changes/missing-production-runtime-variables-in-preview.md
@@ -0,0 +1,6 @@
+---
+type: fixed
+---
+Missing production runtime variables in preview deployments when the variable has no preview variable
+
+- A preview gets these production runtime variables again, except when `PR deployment access` is public. The deployment log lists each variable that a preview does not get
diff --git a/app/Jobs/ApplicationDeploymentJob.php b/app/Jobs/ApplicationDeploymentJob.php
index 8d68902ffa..2c017aa9dd 100644
--- a/app/Jobs/ApplicationDeploymentJob.php
+++ b/app/Jobs/ApplicationDeploymentJob.php
@@ -461,6 +461,7 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
 
         try {
             $this->validateDeploymentEnvironmentVariableKeys();
+            $this->warnAboutPreviewVariablesNotPassed();
             $this->ensureRegistryImageForMultipleServers();
             $this->ensureRegistryImageIsNotShared();
             $this->warnAboutVolumesOnMultipleServers();
@@ -2184,9 +2185,9 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
                 $envs->push($this->runtimeEnvironmentAssignment($env));
             }
 
-            // A preview from before v4.5.1 also gets the production variables that have no preview copy.
-            if ($this->preview?->keeps_production_values && $runtime_environment_variables_preview->isNotEmpty()) {
-                $previewKeys = $runtime_environment_variables_preview->pluck('key')->all();
+            // The production runtime variables that have no preview variable.
+            if ($this->previewGetsProductionRuntimeFallback()) {
+                $previewKeys = $this->application->environment_variables_preview()->pluck('key')->all();
                 $sorted_environment_variables
                     ->filter(fn (EnvironmentVariable $env) => $env->is_runtime && ! in_array($env->key, $previewKeys, true) && ! $this->shouldOmitBlankComposeEnvironmentVariable($env))
                     ->each(fn (EnvironmentVariable $env) => $envs->push($this->runtimeEnvironmentAssignment($env)));
@@ -2194,12 +2195,12 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
 
             // Add PORT if not exists, use the first port as default
             if ($this->build_pack !== 'dockercompose') {
-                if ($this->deployedPreviewVariables()->where('key', 'PORT')->isEmpty()) {
+                if ($this->deployedPreviewVariables()->where('key', 'PORT')->isEmpty() && ! $envs->contains(fn (string $env) => str_starts_with($env, 'PORT='))) {
                     $envs->push("PORT={$ports[0]}");
                 }
             }
             // Add HOST if not exists
-            if ($this->deployedPreviewVariables()->where('key', 'HOST')->isEmpty()) {
+            if ($this->deployedPreviewVariables()->where('key', 'HOST')->isEmpty() && ! $envs->contains(fn (string $env) => str_starts_with($env, 'HOST='))) {
                 $envs->push('HOST=0.0.0.0');
             }
         }
@@ -2805,6 +2806,64 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
         $this->application_deployment_queue->addLogEntry('   Suggested name: '.ValidationPatterns::displayShellEnvironmentVariableKey($suggestedKey), type: 'info');
     }
 
+    /**
+     * A preview can run code from a fork when public PR deployments are on, so it must not get production
+     * values. A preview from before v4.5.1 keeps them, because it was deployed with them.
+     */
+    private function previewUsesProductionValues(): bool
+    {
+        return ! $this->application->settings->is_pr_deployments_public_enabled || (bool) $this->preview?->keeps_production_values;
+    }
+
+    /**
+     * A preview gets the production runtime variables that have no preview variable, as before v4.5.1.
+     * This needs at least one runtime preview variable, so previews without preview variables stay
+     * without production values.
+     */
+    private function previewGetsProductionRuntimeFallback(): bool
+    {
+        return $this->pull_request_id !== 0
+            && $this->previewUsesProductionValues()
+            && $this->application->runtime_environment_variables_preview()->where('is_runtime', true)->exists();
+    }
+
+    /**
+     * Log the variables that this preview deployment does not get, so users know what to add.
+     */
+    private function warnAboutPreviewVariablesNotPassed(): void
+    {
+        if ($this->pull_request_id === 0) {
+            return;
+        }
+
+        $previewVariables = $this->application->environment_variables_preview()->get();
+        $skippedKeys = $previewVariables->whereIn('id', $this->previewVariableIdsWithProductionValues())->pluck('key');
+        if ($skippedKeys->isNotEmpty()) {
+            $this->application_deployment_queue->addLogEntry('⚠️ Public PR deployments are on, so this preview does not get the preview variables that still have the production value: '.$skippedKeys->implode(', '), 'stderr');
+            $this->application_deployment_queue->addLogEntry('   To use them, give them a preview value in Environment Variables > Preview Deployments.', type: 'info');
+        }
+
+        $getsRuntimeFallback = $this->previewGetsProductionRuntimeFallback();
+        $passesBuildtimeVariables = $this->deploymentPassesBuildtimeVariables();
+        $missingKeys = $this->application->environment_variables()->get()
+            ->reject(fn (EnvironmentVariable $env) => $previewVariables->contains('key', $env->key))
+            ->reject(fn (EnvironmentVariable $env) => $this->build_pack === 'dockercompose' && $this->isGeneratedDockerComposeEnvironmentVariable($env))
+            ->map(function (EnvironmentVariable $env) use ($getsRuntimeFallback, $passesBuildtimeVariables): ?string {
+                $missingAtRuntime = $env->is_runtime && ! $getsRuntimeFallback;
+                $missingAtBuildtime = $env->is_buildtime && $passesBuildtimeVariables;
+                if (! $missingAtRuntime && ! $missingAtBuildtime) {
+                    return null;
+                }
+
+                return $env->is_runtime && ! $missingAtRuntime ? "{$env->key} (at build time)" : $env->key;
+            })
+            ->filter();
+        if ($missingKeys->isNotEmpty()) {
+            $this->application_deployment_queue->addLogEntry('⚠️ These production variables have no preview variable, so this preview does not get them: '.$missingKeys->implode(', '), 'stderr');
+            $this->application_deployment_queue->addLogEntry('   To use them, add them in Environment Variables > Preview Deployments.', type: 'info');
+        }
+    }
+
     /**
      * IDs of preview variables that have the same value as the production variable with the same key.
      * Coolify copies each new production variable to the previews. With public PR deployments, a
@@ -2818,7 +2877,7 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
             return $this->previewVariableIdsWithProductionValues;
         }
 
-        if ($this->pull_request_id === 0 || ! $this->application->settings->is_pr_deployments_public_enabled || $this->preview?->keeps_production_values) {
+        if ($this->pull_request_id === 0 || $this->previewUsesProductionValues()) {
             return $this->previewVariableIdsWithProductionValues = [];
         }
 
diff --git a/tests/Feature/ApplicationDeploymentControlVarFilteringTest.php b/tests/Feature/ApplicationDeploymentControlVarFilteringTest.php
index 9ad41b1846..3db71b3135 100644
--- a/tests/Feature/ApplicationDeploymentControlVarFilteringTest.php
+++ b/tests/Feature/ApplicationDeploymentControlVarFilteringTest.php
@@ -948,8 +948,9 @@ it('filters docker compose generated service variables from build args', functio
     expect($envArgs->has('SERVICE_URL_APP'))->toBeFalse();
 });
 
-it('does not fall back to production vars when preview copies are deleted', function () {
+it('falls back to production runtime vars without a preview copy only when public PR deployments are off', function (bool $isPublic) {
     [$application, $server] = makeDeploymentControlVarFixture();
+    $application->settings()->update(['is_pr_deployments_public_enabled' => $isPublic]);
 
     createApplicationEnvironmentVariable($application, [
         'key' => 'APP_NAME',
@@ -967,16 +968,19 @@ it('does not fall back to production vars when preview copies are deleted', func
 
     $application->environment_variables_preview()->where('key', 'APP_NAME')->delete();
 
-    [$job, $reflection] = makeControlVarFilteringJob($application, $server, [
+    [$job, $reflection] = makeControlVarFilteringJob($application->fresh(), $server, [
         'pull_request_id' => 99,
     ]);
 
     /** @var Collection $runtimeEnvs */
     $runtimeEnvs = invokeDeploymentJobMethod($job, $reflection, 'generate_runtime_environment_variables');
 
-    expect($runtimeEnvs->contains(fn (string $env) => str($env)->startsWith('APP_NAME=')))->toBeFalse();
+    expect($runtimeEnvs->contains(fn (string $env) => str($env)->startsWith('APP_NAME=')))->toBe(! $isPublic);
     expect($runtimeEnvs->contains(fn (string $env) => str($env)->startsWith('PREVIEW_FLAG=')))->toBeTrue();
-});
+})->with([
+    'public PR deployments off' => [false],
+    'public PR deployments on' => [true],
+]);
 
 it('does not give production runtime values to a preview copy that is not a runtime variable', function () {
     [$application, $server] = makeDeploymentControlVarFixture([