When I tested the reset button on this forum (incognito window), the button was disabled for a little while and when I received an ajax response from the server, it became active again (with the error message I received).
Yes, it does grey out, briefly, then re-enables. I’m not sure I was looking closely enough at the time, and could have missed it going gray. - I do remember being surprised the button was available, and assumed I’d just not clicked it.