I have a network set up with Firewalla Gold as the main router.

The set up I have is:

ISP -> Modem -> Firewalla Gold -> Deco X55 (main) -> Eth Switch -> Deco X55 satellite nodes all connected through ethernet switch for a wired backhaul.

After the recent firmware upgrade I am seeing wifi being unavailable consistently. I tried deleting the entire network and starting from scratch (the deco topology) and set it up as router (in which case wifi works), but if I switch to AP mode as I don't want Deco to do the routing, all deco's turn to Red led and wifi stops working completely.

The same set up (Deco's in AP mode) was working absolutely fine till a couple of weeks back. Any ideas of what could be going wrong with this set up and how can I try fixing it?