Skoda Fabia door lock mechanism

Hope someone can help.

I have a Y reg Skoda Fabia without central locking.

I've trawled previous posts regarding problems with Skoda door locks and thought I'd found the answer. Bought replacement paddle and took out lock from drivers side door. Seems to be working ok and regreased and replaced still same problem.

I can use the key to lock the door however I cannot open the door even though the lock is rotating as usual. If I use the interior lever the door unlocks normally.

Is it something that I overlooked or will I have to resort to taking off the interior door panel?

Thanks for your assistance.