What worked for me was a combination of both answers. I tried resetting the tool to no avail, so I tried Mglush's suggestion of using the Select>Modify>Feather option, and I noticed it turned the feather option on the tool back on. The Menu option overrides the tool option though, and since I don't want to have to open a menu everytime I need to make a change, at this point I tried resetting the tool again with the right click option. This worked to clear the Menu override and left the Tool feather option un-greyed for future editing.  ... View more

I'm also running 24.4.1 with the same issue. Updating my driver (RTX 3070 Ti) and rebooting didn't work, disabling 'Use Graphics Processor' under Preferences>performance DOES work, however, I am using artboards, which needs this option checked on. 😞 ... View more