Just installed MSFS 2024 Steam edition in PC Win11.
It ask me to login in the Xbox acount. I can select my account but I am not able to introduce the password because the password textbox loses focus constantly. So I can not write the password.
In full screen I can not even use the mouse. In window mode I can use the mouse.
If you click in the textbox you can insert one letter of the password, but you must be real quick. Then click again and instantly type the second letter before focus is lost again. Painful and absurd, but that‘s how I got my pw finally entered..
The same thing happened to me yesterday with planner.flightsimulator.com. No honeycomb in my case.
I have disconnected my Winwing joystick and throttle and tried again.
Problem solved.
Many thanks to all of you for your quick assistance.
In my case, I’ve just discovered that FFB2 was the cause 
The stick was to the right, changing the focus of the textbox.