@GTA1216 One thing to check is some devices do not allow some special characters in the password and/or SSID. For example it may not allow a $ sign but allow a * sign.

@Mb1189 Turn the WIFI off on your PC and try again.

@Mb1189 try turning off the modem, connect a Pc direct to the router via ethernet.

@Pet_Ranch_tx I suspect that QB is wants to connect to a specific IP that it used in the past. Not sure if your computer or QB needs resetting. Try a different computer, different browser, clear...

@aikeber I would first attach a pc to the modem/router and check the speeds. Then I would set the modem/router in bridge mode and attach the TP Link router to it and have all of the extenders and AP...

@Evil_Oliverlord I have seen things change with Firefox as they add new security features. May want to try clearing history, cookies, .... and see if that works. I use my iPad most the time I sign on...