Screen tearing

[i00]

Functional ... but there is a lot of screen tearing - NOT VSYNC - but shaking in segments!

Any ideas?
Thanks

[annata20]

When your monitor's refresh rate and GPU's frame rate are out of sync, dordle screen tearing happens. It can be identified by a horizontal split in the image at one or more locations.

[lunaterra]

A display device that displays information from many frames in a single screen draw is said to be exhibiting screen tearing in a video display.