C965 bafang display/sensor issue

[AlexVel]

I have a Bufung midrive setup , worked great for about a year but here is a recent issue: Drive and throttle seem to work fine, but the display C965 (3 button) turns off after about 20 seconds and leaves a flashing blank battery and a flashing motor signal on the display even though the battery was fully charged a night before and can go for another week. The motor seems to keep working fine too, applying the breaks during the drive restores the display, but after 20 seconds its gone again...also PAS does not change level of assist when display is flashing empty battery and motor even though I can feel everything is working...what could be wrong??