cloud.disroot and u2f devices

I tried to login from one of my Chromebooks and it failed because of the u2f. I did get past the login, but the light did not start blinking on the u2f device and pressing the button did not give access. I then used a dropbox account with the same device and it worked without a problem.
I then went back to my normal laptop’s Chrome-session and added 2 more devices to cloud.disroot, which worked. (this proves that the routines that make the leds-blink and read input from the u2f are working correctly. i.e. it is most likely a software problem after uid/pwd the paart that tries to read the u2f does not work correctly).
I did make sure I had my backup-codes, which I do. but I could not log in to my cloud.disroot account from Firefox.

I am afraid to log out with Chrome, because I am concerned that I may no longer be able to log in.
Does anybody else have problems with Chrome or Firefox no longer being able to log in with the u2f device that still does work on other sites?
Could it be something wrong on my side, or is there something wrong with the nextcloud login that stops at the u2f check?

Thanks,
Y.

I do not see anything that could point any issue in the logs (unless your username you are testing with is different). I know not very useful, but perhaps you could disable 2FA, re-enable it, add devices and get new backup codes.
Was the feature working before? I have no u2f device to test it with.

It has certainly worked before. But I am not 100% certain where (which device/which browser) I tested it.

I am wondering if others with u2f devices can still login. I use Manjaro-Linux with Chrome and Firefox as well as Chromebooks (with Chrome).

Hmmmm… If it worked before, I would suggest disabling 2FA and restarting the process from scratch.