Command key doesn't repeat as expected

[stevenlundy]

When the command key is used as a modifier it doesn't seem to allow other shortcuts to fire until the command key has been lifted again.

See example:
https://codepen.io/stevenlundyseesaw/pen/LYEdVBL?editors=0010
Command left and right should move the circle left and right without having to lift the command key
If you change it to another modifier (alt, shift) it works as expected

[stevenlundy]

Here's an explanation of what's probably causing this. https://stackoverflow.com/questions/25438608/javascript-keyup-isnt-called-when-command-and-another-is-pressed