SP4 Pen Pressure Not Working in Art Programs

Hello there!

I just got my SP4 today, and was really excited to try it out... only to spend hours simply trying to figure out how to get my paint programs to work. I got the i7 model with 8gig RAM.

I do not have pen pressure or stabilizing in SAI, Krita or Photoshop, but I do have it in Clip Studio. I tried downloading the Wintab driver and it does nothing. I have uninstalled and reinstalled all of the programs, including the driver, restarting, and so far nothing has worked.

I've been searching everywhere for a fix, but haven't found much. I would very much appreciate any help on this issue! I was hoping to be able to do some of my illustration work on this thing, but it's not looking good so far.

Thanks in advance for any advice!