Hey there!
I’ve recently picked up Zbrush about a few weeks ago and I’ve ran in into an issue with navigation as of yesterday. Everyday I go into zbrush and set up to practice sculpting. Yesterday I started to notice a glitch I think with my navigation when utilizing the hotkeys.
*As a Disclaimer, I’m using a Surface Pro 6.
The hotkey’s were the first parts of zbrush I learned so I’ve definitely got them down. However when I’m moving my sculpt with ALT+Click/Drag pen and then proceed to let go of either ALT or take my pen off of the screen…the sculpt zooms in or zooms out… again in this case it’s either one and it is driving me nuts to say the least. I know that when holding down ALT+Clicking/Dragging pen then releasing ALT is the shortcut for zooming in or out so I tried taking my pen off of the screen first and then letting go of ALT to see if that would solve it but it did the EXACT same thing. I wasn’t having this problem before, but now it’s being weird and glitchy. I can’t seem to freely move my sculpt or even rotate it without it zooming in or out. Also to add, when I am rotating my sculpt and I want to snap it into place with “shift” the sculpt no longer snaps into place anymore. It act’s like it wants to but once I let go of shift or take my pen off of the screen it slightly adjusts to be a bit off and then leads me to toying with it in order to get it at the angle I was aiming for.
I’ve tried updating Zbrush and that doesn’t seems to work. Neither does restarting my Surface or the program. I am a bit at a dead end and don’t know where to go from here. I don’t know all the ins and outs of Zbrush yet but I know the basic’s enough to know something is up- or that I may just be missing something… at this point I just don’t know 
I’d really appreciate any help to figure out what’s going on so that I can continue sculpting.
Thanks!
Leo