Brush gets stuck when I try to to subtract part of a mask

I am having a problem with both Lightroom Classic and Lightroom CC. When I use the brush tool to subtract part of a mask Lightroom stalls. The brush itself will continue to subtract, but nothing else works. I cannot move on from the brush to another tool, close the mask, or do anything else. The app freezes. This does not occur when I use the brush to create a mask, only when subtracting. The apps will not even shut down. I need to force quit. 
Macbook Pro, M4 chip, 48GB RAM. MacOS 26.0.1 Tahoe.
Lightroom Classic 15.0
Lightroom CC 9.0

Is anybody else experiencing the same issue?