Mouse-slider interaction jumpy in Develop mode

[joseph motto]

My ability to easily move the sliders in Develop mode varies markedly. Sometimes I can grab the slider and it moves nicely. But more often it takes repeated captures to move it and then it often jumps forward or backward to zero point. Same with the cropping. As soon as I try to grab the corner or side and adjust the size of the crop it jumps out of crop. Only happens with LR6 Classic, never in Photoshop.

[GoldingD]

Do you have a WACOM tablet attached/

[GoldingD]

Do you have another mouse?

[GoldingD]

LR6, what exact version? v6.14?

[GoldingD]

I forget if V6 had this, think it did, but was very buggy.

In /preferences/performance/ is use Graphics Processor on or off, turn it off, see what happens.

[joseph motto]

Yes, I have LR 6.14. No, no Wacom tablet. I have been using Logitech mouse only and it does not seem likely to be the source of the problem as it is only a problem in LR.

I will try the last suggestion later today.

[joseph motto]

I turned off the Graphics Processor option and tried working one image and it does seem better albeit not perfect. Unfortunately I had just completed working a large number of images and have not to require processing currently but will leave it off and see what happens when I next process images. Thanks for the suggestion; I hope it holds up.

[GoldingD]

I have been using Logitech mouse

That causes me to ask if you have installed and running the Logitech Options plug-in? That plug-in is very buggy, causes all sorts of issues, normally just irritating issues. That plug-in is  not the driver fir the mouse, it just allows you to assign buttons on the mouse and/or keyboard to cause LrC actions.

[joseph motto]

No, I am not using a Logitech Plug-in.

[joseph motto]

After gettting back to processing I find that turning off the Graphics Processor tab had no effect on the jumpy mouse-slider or crop interactions and I remain frustrated with the effort required to adjust these areas in LR.

[GoldingD]

Consider resetting the preference file. Resetting the preference file is Adobe speak for deleating the preference file and then letting Lightroom Classic to recreate it.

The preference file can get corrupted, resulting in odd behavior. Some people have a knee jerk reaction in thinking they need to uninstall then reinstall Lightroom Classic, maybe that could be called for, but it would be better to first reset the preference file.

Be aware that resetting the preference file will result in Lightroom Classic creating a new catalog instead if opening your previously opened catalog (normally) so make sure you know where your catalog is. 

Be aware the resetting the preference file will revert some settings in Preferences to defaults. So be aware of what you have changed, so that you can put those back the way you want them.

some links:

https://lightroomers.com/replacing-the-lightroom-preference-file/745/

https://www.youtube.com/watch?v=bARt-hoCc2Q

https://helpx.adobe.com/lightroom-classic/help/setting-preferences-lightroom.html

https://helpx.adobe.com/lightroom-classic/kb/recover-catalog-images-resetting-lightroom.html