Very short loss of power EP8

[Spaceballz]

1 year old Commencal no problems at all until now. Once in a while in lowest gear climbing steep, motor shuts down for a very short time, like less than a second then starts again. Cleaned everything really nice, checked the sensor and wire, everything looks ok. Any tips? I have not used or installed the etube app at all, does that show any codes or anything? When motor shuts off I can see a code flash for a milisecond but cannot read what it says before it's gone.

Any advise much appreciated! Thanks!