smooth brush

That's weird ssenyr

Are you maybe holding CTRL when trying to smooth? That would 'invert' the Brush behavior and set it to 'enhance detail' in stead of smoothing.

spikeyxxx

I working with ctrl and settings of the smooth is (direction +) and it  scratch, i tried (direction - ) but is pulling out the vertex like spike 

 i delete this file project and return back to the old file, the smooth is working perfect maybe blender bug ?

Glad it's working now :D

I have no idea what was causing it...