Today (02/28/20) I did a firmware update (to tp-link AC750 RE220) via the Tether App and now its pretty much bricked. I've tried every kind of connection, resetting it, etc. and nothing works. The most obvious symptom is that the default SSID (TP-Link_Extender) is never never generated. I can't find this wifi network from my phone, desktop, or laptop. It just doesn't exist so there's no way to connect to it or it to anything else.

Any suggestions?