Can you upload that video somewhere where it just plays? Like: embed it in your post?
Does that also happen when youare in CPU Preview?
This is the latest version. What's the problem?
Sorry to hear about this. Would you mind sharing version of the OS & Illustrator? Does it happen with a specific file or all?
In addition to the suggestion given by Monika, please try disabling the GPU Performance under Preferences > Performance and let us know if it changes the behavior.
Looking forward to your response.
What kind of device are you using?
Which graphic card, which monitor?
Any additional devices plugged in?
Do you have third party plugins installed in Illustrator?
When I used the Korean version, there were no abnormalities, but when I removed it and installed it again, I had a problem like that.
I'm using Samsung laptop. The graphic card is Intel(R) UHD Graphics 620.
No additional device is connected and don' use third party plug-ins.