Windows 10 PIN that contains letters and numbers isn't automatically accepted

when PIN in windows 10 contains letters and numbers, Windows doesn't automatically accept it unless user presses ENTER. but if the PIN only contains numbers (which is by default), then pressing ENTER is no longer necessary.
it's been like this for the past few months but now that I'm reporting this I'm using Windows 10 insider fast ring build 19582

https://aka.ms/AA7py5p