I’ve been noticing this for a short while now, because I use the search bar a lot. When the focus is in the search bar, i.e. the text cursor is happily blinking along, the bar cannot be closed with the Escape key anymore. If I move input focus away from the search text field, for example with the mouse or the tab key, then it works again. Search next/previous with (Shift+)F3 is also affected.

I just updated a machine which hasn’t been run in a few weeks and with it I could confirm that this change happened somewhere between version 20.12.0 (which was installed until now and is unaffected) and 20.12.1.