Photoshop V21.2 is slow with weird issues and unusable.

[Shiba-Inu]

Last month I was happily using Photoshop V20.01, Animate and Illustrator all open and swapping between them, no issues.
With the update to V21.2 I can't even use Photoshop on it's own just doing a drawing!
After about 20 mins it becomes REALLY laggy and then will start drawing the previous stroke when you're drawing the current one, which is no help at all. Then it started doing wird block stuff with the pencil (brush) and I gave up and went back to V20, which is fine.
This has happened for 3 days now and I've been through all optimisation setting. Nothing changes it (although I think it got worse!)>
I'm using I7-6700 CPU, 32GB Ram, SSDs. My video card is only a GeForce 210 (can't update drivers) but everything was working perfectly last month!

Help! .....Please 🙂

[Sahil.Chawla]

Hi there,

Sorry to hear about the laggy experience with Photoshop, could you please try disabling "Legacy compositing" located in Photoshop's Preferences > Performance, then relaunch Photoshop and let us know if it helps?

Regards,
Sahil

[Shiba-Inu]

Hi, thanks for your reply.
I'll try that and update this post.

[Shiba-Inu]

Ok, just tried that but after about 10 minutes Photoshop starts to only draw the previous stroke.
i.e. you draw a stroke - nothing happens, you draw the next stroke and it actually draws the previous one. 
The same file in Photoshop 20 is fine.
The file is a drawing (black/white) with only 3 layers and is 371MB in size.