After switching the router to acces point mode, I lost access to the configuration built in web site as also via the Thetter App.

Via web browser I can access the login page, enter the local password I set during the initial setup but receive a error saying "wrong password".

I did reset to factory default a couple of times, set a local password but after switching to access point mode the same happen again.

The access point works fine but because this problem I can not change the WiFi SSID and default password.

Any idea how to regain access?

Thanks in advance