Sent the car to the workshop. Have most of the symptoms related to the real electrical module but surprisingly, some are still working.
Found a number of threads on bimmerpost found after using Searching for the right words.
Puma reset of REM >
https://f30.bimmerpost.com/forums/sh....php?t=1385766
https://www.google.co.uk/amp/s/bmwte...dule-died/amp/
Replacement of REM >
https://f30.bimmerpost.com/forums/sh....php?t=1524239
https://f30.bimmerpost.com/forums/sh....php?t=1640413
Loose connector on REM (possible since I changed my battery recently?) >
https://f30.bimmerpost.com/forums/sh....php?t=1627721
Will update in a day or two time when I get the car back!