Radio remote control/central locking without function

Moin Moin, on the Mazda 626 (Bj 99) of my father-in-law, had a problem with the ZV/Ffb. Do not know the car otherwise. He approached me because the radio remote control suddenly did not work anymore. At that time he had already changed the battery in the remote control and because of failure got a new remote control (original of Mazda). Unfortunately he also got it with the new one not running. I thought it would be the learning procedure and got me the thing today times Unfortunately, the learning procedure does not work. The car does not seem to be able to call the mode. Normally, the ZV should show a movement in the procedure after the door contact switch has been operated 3 times. Nothing is moving here. I checked the door contact switches for function, the light gets darker when you press them. However, I noticed that the ZV itself shows a strange behaviour: I assume that all doors through the ZV open/ge If you open/close the driver’s door manually with the key over the lock, don’t you think? At least this is how it works on the passenger side. If I use the key on the passenger side, open/close all doors including the driver’s door. If I use the key on the driver’s side, only the driver’s door can be opened/closed. All other doors are not addressed. That doesn’t seem normal. Ht functional Ffb is responsible? Where is the error here? Many thanks and greetings!