An issue with pen pressure

Hi!
I know this is a common asked question, but I wasn't able to find anyone with exactly my issue. Sorry if I am bad with terminology when writing.

I own a Wacom Intuos, and use Photoshop on a Mac (don't know which version right now). When I test the pen in the settings, my laptop recognize pen pressure, but inside the program it changes somewhat randomly. Sometimes the pen pressure can be at full, and right after I switch to a Chrome tab for example, the pen pressure is weak, almost invisible. This switch doesn't happen every time when switching tabs, but the pen pressure is always set to a certain range (opacity at 100% wont be lower than 80-90%, while when opacity is around 10%, it doesn't become higher than 20%). Once in a while I can't draw either, and I have to quit the program and begin again.

This looks more as a Wacom problem than a Photoshop one I believe, but I'm not sure if it is about the pen or the Wacom program. Would uninstalling and installing it be worth a shot? I had some trouble with downloading the first time, so I'm a little hesitant to do it. Or is it the nib/pen in itself? That would be surprising, because I have not used it much before.

Thanks for any recommendations and help.