Repro:
Go to options>other
Hover over Delete Achievement so tooltip appears
press esc.
Works on main menu and ingame, tested a few other (but not all) tooltips but those killed themselves correctly.
[0.16.3] Delete achievement tooltip remains on screen
Re: [0.16.3] Delete achievement tooltip remains on screen
Thanks for the report. It's now fixed for the next version of 0.16.
If you want to get ahold of me I'm almost always on Discord.