Brush Tool Bug - Blocked from editing

I am having an issue where I am unable to bring the brush tool across an image I am editing.  I can deselect  brush tool and used other tools fine but when I select the brush tool the cursor stops at the edge of the photo and I can not bring it on the canvas.  This is immediately fixed with a different tool selected.  I see the same issue in Lightroom.  I don't know if I have a setting wrong or its a bug.  The issue seems to be fixed by restarting the program.  This causes real issues when editing and the bug appears and my work is stopped.