Presets suddenly stopped working

I have been using Lightroom classic for about a year, and suddenly my presets stopped working. When I click and hover my mouse over the preset, the effect seems to work, but as soon as I move my mouse somewhere else, the effect is gone.

The one thing I did that may have contributed to this problem is I checked "Store presets with this catalog" in preferences. Then I unchecked it. After that, they stopped working.

Here are the steps I have made to fix this:

- updated to latest software (computer OS and Adobe)

- Reinstalled LRC (twice)

- restarted computer

- deleted LRC preference file

- Optimized catalog

- contact Adobe tech support...

I have contacted Adobe Tech support about this and I did the screen sharing so they could take control and look at everything. I've done this twice, and both times, when they were done, the problem was fixed. Then I continue to use it, and eventually the problem comes back again. I tried to follow along with the tech to see what they are doing but I may have missed some. The previous time the tech unchecked "Use Graphics Process", and also increased cache from 5.0GB to 15GB.

Here's some other info that might be helpful:

- the exact same presets in Photoshop Camera Raw work fine

- the exact same presets in Lightroom CC work fine

My computer is 2013 Macbook Pro running latest OS.

Any help is appreciated