2017 Volvo S60 - Rear Backup Sensor Fail

Rear sensor system does not beep intermittently. Dry joint?

Dry joint , have no idea what you think that is but if you are the original owner your warranty should cover this problem . And if you mean the rear parking sensors see if they are nice and clean.

Dry joint = poor
soldering in electrical system => intermittent faults, as noticed in our
S60.

It would appear to be
in the system itself as it happens on both sides. Anyway, one sensor has been
replaced after a collision near it.