Rear parking sensor failed without error

[SkipjackUK]

so after 3 hours of fruitless endevour I'm one step up and two steps back.

bought a replacement sensor from ebay (non volvo) after diagnosing with VIDA it was faulty sensor #3.

stripped it all down and tried replacing sensors but got some weird results with vida? even with all sensors removed it was reading sensor 3 OK and the others faulty?

so i have a few questions for those with knowledge in this area.

1. Park assist button on ICM hasnt worked (illuminated) for a few months, is this a failure of the REM or does it have a fuse blown possibly?
2. Could the REM be faulty?
3. the loom looked ok, no visible damage. however does it need a new loom
4. shall i just hope for the best and buy 4 genuine volvo sensors
5. go the whole hog and just get a loom and 4 sensors

can anyone make sense of the VIDA screenshot?

[SkipjackUK]

I'm new to VIDA. Do I have to reset somehow after changing one.

Ta