If you make Ctrl you key for changing brush size(Drag Value) in keyboard preferences, every time after pressing ctrl+z you next brushstroke will be consistently ignored.
Thanks for this report. The undo action was not designed to undo the tool’s configuration, so this is not a bug. In any case, this topic can be left open to collect impressions from the community.
Hi @LuciusPollucius, I was able to reproduce this bug, adding a GitHub issue to keep track to this: