FIDO2 authentication interface bug during first device unlock

How to reproduce (for example, not only protonmail):

  1. Register protonmail account and enable 2FA

  2. Add Trezor Safe 5 as Security Key

  3. Logout from protonmail and remove Trezor from USB port.

  4. Refresh login page (before every test you need always refresh the login page) and login into your account

  5. Choose Two-factor authentication > Security key.

  6. Insert the Trezor, unlock it and enter PIN code.

You will see that after unlocking with a PIN code, the screen on the device will shortly shown once (for about a second) with FIDO2 authentication and it will disappear immediately. In this case, I will need to press the Authenticate button again and do everything again to login into my account.

I hope the problem with FIDO2 authentication screen disappearing upon first unlocking will be fixed.
To avoid unnecessary movements, so that it doesn’t irritate the users.

I recorded a short video of the problem. If needed, tell me where to send it if necessary.

Information Updated:
Win 10 Pro latest, Mozilla Firefox

Glitch detected on (can be more but it will enough for test):
google
proton (me) mail (some activation conflict with Safe 5 and Model One, they recognized by service as one device, not as both different)
github
tuta (com) mail (security popup window disappear after about 45 seconds)

After glitch happened then after one minute the security popup window will refresh in the browser and in this case FIDO2 activation screen appear again on the Trezor and does not disappear.

Some other mail services and this forum works without this glitch.

I have a suspicion that the Safe 5 device Passkey may stop working after some time (account verification fails). I will continue testing and identifying the issues.

Information Updated 2:
I registered the Safe 5 device on this forum as Passkeys:
sshot-67

When I logout and try to log into my account via Passkeys, the first try I get an error:

Everything works on the second try. Why is there an error on the first try?
You can clear cookies and site data in your browser before logging in to check for sure.