possibly non-wifi (netgear prosafe...) routers too...
my fvs336gv3 and fvs318gv3 (318 EOL support wise anyway) routers isolated right now but...I think they may have used the same setup for certs. so if I am right same "bad" wifi could also be an issue with them.
due to setup not an issue for me right now and I don't have the knowledge on how to check anyway.