From a post on the LR general forum:
This appears to be a UI bug on Windows that is causing me enormous frustration and errors.
In
any app that allows mouse selection, it is common to mouse click and then move to a button, menu etc. Or, shift+click and then move to perform an action. Because of the poor performance of LR, it is quite common to move the mouse before LR gets around to processing the click.
When you click the mouse button to select a image (or shift+click to mark the end of a range of selected images), there is sometimes a ~1 second lag before LR responds to the event. That in and of itself is not a bug. However when LR gets around to processing the click event, it appears to read the current mouse coordinates, rather than those packaged with the event. If you have moved the mouse after clicking, it will select the wrong image.
This has caused me to incorrectly tag images, and sometimes inadvertently delete the wrong image.
The machine is fairly high-end (Core-i7 with 8 physical cores; 32gb RAM; GeForce GTX 1060 video card with 6gb; system, catalog and cache all on SSDs). I have performed all the performance tricks suggested by Adobe. My catalogs typically have 5,000-10,000 images.
I am seriously considering looking at alternatives because of the frustration caused by this bug.
Are there any suggestions out there, or is there some way to get Adobe to fix this bug?
Thanks,
Rich
https://forums.adobe.com/message/10770268#10770268