Resetting the AP using the reset / FactoryDefault credentials only work when done via the console port. They will not work when SSHing into the AP.
Please console into the AP using speed (baud rate) 115200 and use above credentials to reset.
As for the browser part, since Adobe Flash has been discontinued, you’ll need to download the WiNG-Man App and use said app to access the AP via GUI.
https://extremeportal.force.com/ExtrArticleDetail?an=000085391
Thank you
Christoph S.
