I know it has been quite some time, but the issue has not been fixed with the latest updates. However, I have found a band-aid from an old forum discussion where this has been an issue before. It appears to be related to hyperthreading or the CPU threads. I saw two fixes in the earlier forum. The two options are,
1. Make sure that photoshop is open, open task manager, click on the details tab, right click on Photoshop, and then "set affinity."
It will show you all of the cpus/threads that Photoshop uses. I have a 14 core processor (28 threads), so I removed cpus (threads) 14-28, leaving 0-13 with ticks in the box.
This COMPLETELY alleviates the problem. Unfortunately, it seems I have to do it EVERY time I open photoshop.
2. This option, unfortunately, will have an effect on performance across all software that can utilize the feature. Turning off hyperthreading in the bios also fixes the problem. You only have to do this one time.
It seems like this has been an issue in the past that has been fixed before, but the issue seems to have worked its way back into the code.
I'd love to hear if anyone else has any alternatives!