Set-Up fails for new U2F device from Firefox to Android device

I’m currently unable to add a device for two-factor authentication. Logged in to GitLab:
User Settings > Two-Factor Authentication > Account

Android is plugged into laptop using USB C. Device is unlocked and recognized by the laptop. Google Authenticator is installed on device.

Attempt to Register Universal Two-Factor (U2F) Device by pressing Set-Up New U2F Device button. Pop up to connect and authorize or cancel has only cancel option. No button appears on device.

Any help would be much appreciated!