Hi!
When I try to login after a fresh install I get an error indicating my password is wrong. the cause is the wrong keyboard layout (I’m non-US). But in the COSMIC greeter it is not possible to switch the keyboard layout. There is a button for it, but the popup-list is empty.
I tested it with Fedora COSMIC Spin 44 and with Fedora COSMIC Atomic 44, downloaded today.
Using Pop!_OS the COSMIC greeter works fine. After installation the correct keyboard layout is set and the keyboard selection works.