@GiantHogweed Here's a guide on how to bridge a DSL modem router and use a wireless router connected behind, thus avoiding double NAT in your LAN. In fact, other brads DSL modem routers have so...

I believe that in this particular case an upgrade path should be defined by @Kevin_Z in the thread, where the AX53 new FW release announcement was made.

@Rarespawn Did you check if the devices connected to the A7 receive a proper network settings i.e. an IP address in your main modem DHCP range as well as a valid Gateway and DNS.

@Slimmy6828 Since SR203 is a dual band wireless router, RE205 would be a better choice than WA850RE (which is a single band RE). Despite that, they both should be able to connect to the SR203 as long...

@tlkounev You didn't miss anything - BE800 just doesn't have any backup connectivity implemented - here's its user guide. The backup connection feature is implemented only in their 3G/4G modem...

@SabbirLeon If you don't use the mesh feature better turn it off - this way you'll get a lower wireless interference around you.