2006 Tribute V6 FWD w/ command starter.

Initially the remote entry would not work, although remote door lock & command start was ok, with the same remote. Driver side interior door lock/ unlock also does no longer work, nor does the manual unlock feature with the keys, e.g. I can only unlock all doors, incl. trunk manually by hand from the inside.
Next the rear window wipers stopped functioning.

Initially we though there was an issue with the command starter but this did not seem to be the case, as attested by command start professionals.

The dealership did a diagnosis and determined the CPU (Central Processing Unit) needs to be replaced, or it could lead to a malfunction of all electrical commands.
Needless to say, its a costly affair and apparently it does not happen too often.

Is this a valid diagnosis? Has anyone experienced a similar problem before?
I'd appreciate feedback and info if this indeed could be the case.

Although it is the same Mazda dealership where I purchased the vehicle pre-owned, I am slightly cautious as I had some service issues with them before, on a different model.

Thanks all!

TS