I am having the exact same issue as they are, in order to reproduce it I would recommend spamming a button rapidly, after 10-30 sec of spamming the issue already occurs. It seems like the issue occurs less when I map the arrow keys than with any other key, but it still happens. I am quite certain this is a GRID issue if you are in the control setting it shows you what buttons are being pressed. Once you spam enough every time you press it the correct letter will appear for a fraction of a second and then disappear. as you can imagine this is quite annoying.