my home internet system consists of a linksys router flashed with expressvpn to which i have another TP-link router linked by ethernet at the far end of my home.  to this i have a deco X15 connected by ethernet to this tp-link router.  and to this i have two deco's connected by wifi in the other two areas of the home with poor coverage.  the system works great BUT i have intermittent outages over the deco mesh system. i lose connectivity briefly, which then causes it to reconnect. this whole process takes maybe three minutes but is very irritating to say the least!  it happens several times a day, and i cannot find a cause. my guess would be power fluctuations, but the main X15 and both routers are connected through a battery backup that also controls power fluctuations, so i dont think this is the answer.  mymain router into the home seems to be unaffected.

anyone have any ideas?