fix: update back action to return to previous page or assignment index

app/Filament/Resources/Learning/Assignments/Pages/SubmitAssignmentPage.php

@@ -310,9 +310,10 @@ public function submit(): void
 
     protected function getHeaderActions(): array
     {
+
         return [
             BackAction::make()
-                ->url(AssignmentResource::getUrl()),
+                ->url(url()->previous() ?? AssignmentResource::getUrl('index')),
         ];
     }
 }