I've finally tried ART and it is amazing!

[Teto (Teto The Squirrel fox)]

@a286

Enable Local Contrast, enable Brush Mask, click on “Toggle on-canvas painting with the brush.”. Mouse cursor becomes brush when I move it over the image, everything is fine. Now disable Local Contrast. Cursor remains as a brush, and there is no way now to disable it (selecting hand tool, toggling Local Contrast/brush/etc.), other than closing this editor tab.

Right click on canvas. Problem solved. ^^