5.6.8 flipping not working but it does work in Cinnamon 5.2.7

 * Cinnamon version: 5.6.8
 * Distribution: Arch Linux
 * Graphics hardware and driver used: GTX 1660 Ti, 525.89.02
 *64 bit
 * Attach ~/.xsession-errors, or /var/log/syslog: no such file exist

Issue

When you enable application profiles in nvidia-settings, you can see the FPS of a game or a program and along with it another line which indicates the state of flipping. If it's working, the second line should be all green, reading "FLIP - VSYNC ON". But instead it reads "BLIT - VSYNC ON" which means that flipping isn't working.

Steps to reproduce

1. Create an app profile to display FPS (profile name GLShowGraphicsOSD=true) and then create a rule for any native linux game (for instance: [procname] eurotrucks2 and add the created profile name).
2. Run the game and observe the top left corner. It will have a red word "BLIT" in it:
   

Expected behaviour

Flipping should be always working

Other information

I had reported similar stuff in the past year or so but now I can't find the other report. It may have been removed, IDK. But recently I discovered something which I think is important: flipping worked just fine on Cinnamon 5.2.7 before you removed metacity. I decided to downgrade for a while to see how other things will behave and noticed that flipping works perfectly fine with Cinnamon 5.2.7. So apart from the missing metacity, whatever else is different between 5.2.7 and 5.6.8, it might be the reason flipping isn't working anymore.

Reproduce the issue on Cinnamon 5.6.8 with Arch Linux, the GTX 1660 Ti driver, and the described NVIDIA application profile. Compare the flipping behavior with Cinnamon 5.2.7, focusing first on the reported removal of metacity; done means the game reports "FLIP - VSYNC ON" rather than "BLIT - VSYNC ON".