I'm using Win10 on an original Surface Pro. I've restarted. I've recently run a couple rounds of automatic updates, so I'm wondering if that messed with something in the art programs I use. These issues do NOT appear to occur in other programs (I tested in Chrome, Steam, and Word); the pen works normally in those. Manga Studio is the older version of Clip Studio, but I tested in both and the behavior was the same.
These are all issues while using the pen; they do not occur when using a mouse. Undoubtedly there are more issues, but I'm too frustrated to play with every feature.
-when I click on a menu item like "File", the drop down won't stay open unless I keep the pen touching the screen. I have to drag the pen point down to the item I want, then lift it off the screen, to select that option.
-When attempting to open a file, I can't scroll properly in the file window. When trying to drag the bar down, it barely drags at all then jumps back to the top. Same with clicking the down arrow, it sort of flashes like it's trying to scroll down but can't.
-I started a new file/canvas, and without doing anything (and I was wearing a half glove, because palm rejection went into the toilet with Win10, but that's another post) it zoomed way, way in. I was able to select a tool and use it like normal, after I pinch-zoomed back to normal with my fingers. I tried again with a new file and the exact same behavior occurred, I even watched the paintbrush circle grow as the canvas zoomed.
-In the menu to start a new canvas, you can adjust several parameters. One is the width and height. There's a box with the current number, then a little down arrow drop down indicator. Click that and it expands to up and down arrows, to toggle the size up and down. There's a little slider bar you can use as well. I clicked on the arrow to expand this little menu, and as I just hovered over the slider bar (no screen contact), it was as if I were dragging the slider up and down, but I wasn't actually doing anything/touching the screen. But the program was registering a click-and-drag. The slider tab, weirdly, wasn't moving while I did this. As I drifted the pen tip up and down the bar, the slider tab stayed where it was, but the number rose and fell. I closed the slider window and the number remained where it had "drifted" to. I tried this on another similar control and the same behavior occurred.
I honestly have no idea where to start with this. Everything worked fine before today :(