RBK50 satellite down to 2.4 Ghz connection to router

Dear all,

Last week the satellite went down in its primary connection to the ORBI router to a 2.4 Ghz connection permanently.

I tried all the hints here I could find in the forum: rebooting both devices several time, factory reset and complete new set-up with the ORBI satellite i short distance to the router, changing the country location etc. and today I installed the new firmware 2.1x on both devices but no change.

What to do? Could this be a hardware defect on the ORBI satellite?

thanks a lot in advance for comments / help