This is a new bug that appeared in the Lightroom Oct 2023 Update (7.0) on Windows 10.
Steps to reproduce:
1. Create a few masks, add some random selections like select subject.
2. To a first mask, add brush selection with auto mask on, and intricately trace out some object in your photo.
3. Right click on selection in the masking panel, duplicate selection
4. Drag and drop the duplicated selection to another mask
5. Observe that the brush selection is.... offset by an arbitary amount. It definitely is not in the same position. Also, I cannot drag the brush selection handle to move it around anymore. So now, with this update, I have to manually re-create the same brush selections for different masks....
---
Lightroom version: 7.0 x64 [ 20230927-2320-8b251c5 ] (Sep 27 2023)
NGL Version: 1.35.0.19
WF Version: 6.0 743769e
VF Version: 1.0.135.7
HIL Version: 40409
CAI Version: adobe_c2pa/0.7.6 c2pa-rs/0.25.2
Operating system: Windows 10
OS Version: Windows 10 Pro (2009)
Internal Camera Raw version: 16.0 [ 1677 ]
-----------------------------
I have a 5900X, an RTX 3090 and 128GB of RAM. Yet Lightroom chokes on a fricking 24MP photo.