I'm investigating: it seems that if I access the classic page via http://192.168.50.1 everything works smoothly while if I access from http://www.asusrouter.com/ it doesn't work as well as it should. And this problem happens even in the previous firmware versions.Sorry to hear about your struggle.
for me running in german ist still better and more stable than any 386 bases firmware.
Good luck with further firmware revisions.
In the penultimate version I can access via 192.168.50.1 but in the latest one it automatically redirects me to asusrouter.com. Solutions?