Me too.
I'm on Windows 10 - Version 21H1 19043.1165
Experience Windows Feature Experience Pack 120.2212.3920.0
Latest Windows Store version of Bedrock
This morning Minecraft became unplayable. Going Windowed works, but Full-screen has a short input lag on the keyboard. Just enough to make it unplayable.
This seems to be resolved for me in 1.19.6003.0 I successfully unlocked 3 achievements that I haven't been able to since first reported it.
Thanks guys.