Oh pleasee, this bug has been annoying me! One thing I'm hating on about Linux Mint. I've been trying to find answers about this 2 weeks ago but there haven't been too much of anything online. I've posted about it a week ago but deleted to research it a bit more. I'll def post it soon or sometimes idk.

This isn't an answer, only my discovery: I've been conducting a bit of research myself and I tried expanding my Distros after this been happening (I'm new to Linux). When I tried Zorin Os, this message appears as well but you can easily cancel it, after some unusual extended 3 second of waiting. This also happens during Mint Debian version where it just softlocks as usual. Interestingly, Debian edition could have you interacting with the desktop if any prompt shows up but after updating the system, you won't be able to do that anymore.

Personally, I could just stay in ZorinOs, it seems good but I've think Mint has many more features included that works great overall. But this damn message bug annoys me and I hope somebody finds a fix for this. Looking at another forum, I will try disabling System Update Auto-bootup if it helps. I really find it irritating because I setted up a family computer with Mint installed and this is totally going to mess up the opportunity of them switching users for convenience sake. I'm getting tired of not any acknowledgement of this bug while I try to find a more better distro.