Why I get result:ok and then not found when I try to update picture with Cloudinary ?

Hello everyone, I'm trying to update picture with cloudinary. It was working correctly since one month but now when I try to test it I got AT first {result:"ok"} but the message should be : Media successfully updated! and when I try to update it another time I got : " not found" I didn't know what's the issue behind this error. The pictures are stored in a folder named Testing in Cloudinary Actually I'm no longer having time to resolve this issue because tomorrow I have to expose my project for my graduation. this is the code:

public function updatePicture(Request $request, $user_id){

    $image_details= User::select('public_id', 'user_image')->where('user_id',$user_id)->first();
    $user_image=$image_details->user_image;
    $user_image_split = explode('/', $user_image);
    
    $image_id = explode('.', $user_image_split[sizeof($user_image_split)-1]);
    
    if ($image_id != null) {
                
                try { 
            
                   return Cloudinary::destroy('Testing/'.$image_id[0]);
                    
                     } catch (\Exception $e) { 
                    return $e->getMessage();
                     }
                     return 'not deleted';
    
                }
                $new_user_image = Cloudinary::upload(
                    $request->file('user_image')->getRealPath(),
                    [
                        'folder' => 'Testing'
                    ]
                )->getSecurePath();
                $user = User::find($user_id);
                $user->public_id = $image_id;
                $user->user_image = $new_user_image;
                $user->update();
                return back()->with('success_msg', 'Media successfully updated!');
    
    }
    

Your answers will save my final school year. Thanks in advance for your suggestions