Keyless entry fault

[Sons9801]

Hi All,

I have just registered and I am feeling a bit guilty as I have registered needing your guidance all - HELP.

The purchase / previous owner
I bought a passat gt estate 2015 model 190 brake in a private sale 3 weeks ago
A. The previous owner was a mechanical engineer and replaced the clutch, timing belt, glow plugs and battery. All receipts provided and he told me the battery had been coded to the car
B. He mentioned at the same time as battery coding the stop start was also fixed
C. He mentioned not to have both keys in the car at the same time as the previous owner to him had the keyless entry deactivated
D. We drove the car back from Manchester to Bristol with both keys in the car and no problem
E. Got home took spare key battery out and the car drove really well for about a week - everything worked no faults at all, very chuffed with our purchase, happy days

Since then, happy days are over
1. Keyless entry fault and practically every other alert has sporadically come up as alerts - all just alerts, tyres, parking brake etc
2. The car failed to start on a stop start activation but then restarted about a week ago after using the manual key plus windows up & down
3. We have switched the stop start off each time we drive it and all good up until today
4. We completed a back to factory settings
5. We replaced both key batteries
6. I have noticed that the automatic boot release has been detached. It looks like a bike brake cable under the back seats
4. This morning we couldn’t even get into the car with either key fob. The manual key opened up the doors and we completed 2 above with no success, we left the car for 10 minutes and the car opened and started, back to E above

Next steps?
I’ve tried calling vw but couldn’t get through, probably for the best
A friend is in the motor trade and is coming around on Saturday with his kit to plug and check for faults
As well as checking all of the work from the previous owner, battery coding, clutch etc - could this be causing the issue etc im thinking,
Fault antennas in the doors hopefully rather the dash
Failed temp sensor
Keyless entry module replacement
Keyless entry re activation
Rear boot auto release - can’t be that surely
Recode of the 2 batteries - can be that surely
Main computer - I’d rather not think about that!

Any other ideas from anyone really appreciated.

Kev