I’ve known this bug for a while and have never found a solution. Basically if I start up Zbrush and then either load a tool or import a mesh straight after, most of my keyboard functionality such as brush size and undo, symetry etc. doesnt work.
The only way to get around this is to first draw out a star tool (or can be any other primitive tool from the menu) and mess about with undo/brush size etc with that. Then when I load my ztool in the keyboard shortcuts work fine.
DOes anybopdy have a clue as to why zbrush does this?