Alright so I have a 99 limited and I can program keyless entry remotes (door lock cylinders are tired so I have to help them but I've done it like 4 times now) and when I do this the remotes work properly, the problem is sometime between 10 minutes and an hour later, they stop working completely.

Batteries are new and I can reprogram it again and they will again work for 10 minutes to an hour but then stop. Can I/do I need to replace the keyless entry module itself? If so is it the one in the hatch? Any other ideas?

I have an original fob and 2 replacement ones that are not original, all of them work for a bit but then stop. Everything else related works fine, lock buttons inside, rear window etc but none of the functions on the fob work after they stop working.

Any help or even speculation is appreciated.

The remote function is controlled by the orange ecu in the rear hatch. Checking the wires in the loom coming from the vehicle into the rear hatch would be a good start.