In the develop module the image sometimes breaks up into several large blocks while I am moving a slider. It corrects itself as soon as I release the mouse button but it makes it difficult to judge the correct slider movement.
Windows 10 + Lightroom CC current versions.
It could be a possibility with the display drivers not working properly, did you try disabling graphic card from preferences.
Preferences>Performance>uncheck "use graphics processor".
Yes, that seems to be it. Thank you. The driver was updated just a few days ago - obviously the update is buggy.
You are welcome, glad it worked for you.