Cannot type Username in Manual Login when users are hidden

[w0k3]

What Happened?

Currently the Greeter is unusable in setup where greeter-hide-users=true and greeter-show-manual-login=true.
Fresh install of latest Elementary OS, different computers and VMs. This makes Elementary OS unusable for remote login only (AD, LDAP...) - e.g. school or other organization setup.

Steps to Reproduce

1. Configure lightdm with greeter-hide-users=true and greeter-show-manual-login=true
2. Reboot or restart lightdm
3. If you try to type Username, the field always looses focus. It is not possible to log in.

Expected Behavior

The form should work correctly and allow me to type in a username. Currently it only works when greeter-hide-users=false (default) which is not our use case.

OS Version

6.x (Odin)

Software Version

Latest release (I have run all updates)

Log Output

No response

Hardware Info

No response