RBR50 constantly dropping of wireless connection

Good afternoon,

i'm out of options

i have an orbi rbr50 with 3 satellites.  my house is 250m², i think that's about 800square foot, two floors.

Since the start (about a month ago) my wireless network is dropping every ten minutes, and coming back online a few minutes later, practically unusable for the bussiness i'm running.

my isp is rock stable since i have one computer lan'ed to it and it doenst miss a beat.

i have tried: turning off daisy chain, mu-mimo, armor, circle.. and all the rest advised here on the forums.

i've had my isp place another router, so i could bridge it

i've downgraded firmware, reupgraded firmware and did about 15 factory resets after it

before the router change and the isp router in "bridge", i tried putting it in ap-mode: same thing

nothing works .. it's fine for one day each time, second day the drops are coming back occasionally, by the end of day two my wireless network is as much off as on.

phone support was .. not-supportive, promising me to get a callback by "specialists", but still waiting on it.

does anyone please have any other ideas?