I'll do on weekend if no other help arrives. Thanks.

Update: after some tapping through the menus it showede a warning that Alexa needed a verification. I verificated it through the app and now the power consumption is comparable with before the update. I can just imagine that Alexa tried to verificate en loop.

may a factory reset? to see if that does something?

I recently updated my GTR2 with the usual "optimizations". Since then the battery life went down from 10/11 days to 3 days without changing my usage behaviour. Has anyone experienced the same? Can I downgrade the firmware?

Battery life of GTR2 down after update