P: Smart Preview workflow with Spot Tool creates artifacts

Hi Adobe,
I’m a professional photo editor who works with wedding & portrait photographers and edit thousands of images every month; we exchange Lightroom Catalogs with Smart Previews and I edit just Smart Previews.

I’ve been experiencing this issue with Spot Removal Tool for quite some time:
- green or black squares appear on a place where the Spot Removal tool was applied,
- sometimes this bug messes up the overall exposure making it much darker,
- sometimes this bug also messes up the exposure of applied local masking, making local brushes look much darker or lighter.

It happens very randomly, and not with every image, you never know when it’s gonna happen next.
If I press ‘Reset Healing’, it brings back the normal exposure - but then all my work on healing is gone.
Or, if I press on every single healed spot and slightly move it, it brings desired exposure back - but I have to do it with every spot and sometimes I have dozens of them on one image.

I'm including 2 videos as an example of this bug.

I’m using MacBook Air M1, OS Ventura 13.0, and Lightroom 12.
Until recently, I had a previous version of Mac OS 12 and Lightroom 11, and the problem was there, too.

It’s very frustrating to check a 1000 images wedding, and even if exposure isn’t messed up, there might be some green squares - and a lot of weddings & portraits are shot in the greenery, so it takes a loooot of time to double-check everything.
It’s frustrating because I can miss a green box, it can be exported and delivered to a photographer’s clients with these squares, which is unacceptable.

As for the photographers I work with - some of them don’t see the squares on their end, some say that see them, and these squares disappear after some time.

Anyway, it’s very frustrating when it comes to checking catalogs with hundreds of images, and it feels very uncomfortable because photographers might think that these are just poorly edited images.

To us, ‘photographer & photo editor’ teams working with Lightroom Catalogs with Smart Previews is a game changer, but it doesn’t work properly since I can’t do retouching in Lightroom without worrying it will mess up my edits.

Please, help us with this issue!
I see there was already a thread about it in February 2022, and it wasn’t solved.
https://community.adobe.com/t5/lightroom-classic-discussions/spot-removal-tool-makes-black-squares/td-p/12727026

https://youtu.be/iwjxTvR37JE

https://youtu.be/JmkCjw455mE

This morning I returned to work on the catalog and noticed that the artifacts were gone. I disabled the GPU in the Lightroom settings before I came here for advice and it did not help. It seems to me that the macbook overheated due to long work yesterday, since the coolers were noisy enough.

As for information about the system, here it is:
Lightroom Classic version: 11.0.1 [ 202111111509-eae8952e ]
License: Creative Cloud
Language setting: en
Operating system: Mac OS 11
Version: 11.1.0 [20C69]
Application architecture: x64
Logical processor count: 8
Processor speed: 2,0GHz
SqLite Version: 3.36.0
Built-in memory: 16 384,0 MB

Initial troubleshooting steps:

1. Try setting Preferences > Performance > Use Graphics Processor to Off. Does that fix the problem?

2. Copy and paste here the first ten lines from the menu command Help > System Info. That will tell us the exact version of LR and Mac OS.