Snapshots don't record Lens Blur brush refinements. To reproduce on LR 13.5 / Mac OS 14.6.1:
1. Download and open this tiny catalog:
https://www.dropbox.com/scl/fi/i8vynvlmbidsyexsackaf/lens-blur-copy-bug.2024.06.29.zip?rlkey=nyedxcd...
2. Open the photo test1.jpg in Develop. Observe that it has Lens Blur enabled with Blur brush refinements.
3. Create a snapshot.
4. Click Reset.
5. Select the snapshot. Observe that the Blur brush refinements have been lost.