Everything Is Blurry on Cinnamon 5.0.5 After Restart Or Switching Users

 * Cinnamon version: 5.0.5
   - Using the daily builds PPA? No
 * Distribution: Linux Mint 20.2 x64
 * Graphics hardware *and* driver used: NVIDIA GeForce GTX 1660, using NVIDIA proprietary driver 470.57.02-0ubuntu0.20.04.1
 * Full system details at https://termbin.com/y9ge for the technically inclined because I saw that issue #7555 was 
   closed without resolution due to missing details, so I'm endeavouring to make this as complete as possible.

Issue
When Cinnamon restarts after an update, or when switching users, text, icons, the wallpaper - EVERYTHING - is blurry, just as described in #7555. Taking the advice of that thread, I installed 'scrot' and have attached a screenshot showing this blur.

Steps to reproduce
Switch between two users or manually kill Cinnamon and force it to restart, or install a desklet (like the CPU one in my screenshot) that is one step out of date to force an update with restart.

Expected behaviour
The expected behaviour is that after Cinnamon restarts, everything is fine and there are no issues. However, that's not the case here. Instead, I have to reboot the machine, since the effect does not persist across reboots - but it does persists between user sessions.

Screenshot using SCROT:

Edit
I have a dual-monitor setup, and the screenshot was bigger than 10 MB, which GIT didn't like, so I've uploaded it here instead.

Start by reproducing the blur after switching users or restarting Cinnamon, using the reported Cinnamon 5.0.5, Linux Mint 20.2, dual-monitor, and NVIDIA driver setup. Review issue #7555 and the supplied system details, then verify that text, icons, and wallpaper remain sharp without requiring a reboot.