Brushes doing weird things and I have to keep turning layers on and off to make changes take effect

[artycrafter]

I've been using Photoshop for many years and have had some glitches suddenly arise in the past week that have me confused and frustrated. Firstly, my brushes are not working correctly. They sometimes (but not always) make box shapes that spread randomly all over the image as below. The brushes are also impossible to control, randomly spreading in places I don't want them to go. I'm just using a standard soft round brush.The weird box that appears when I try to use my brushes on an adjustment layerThe brushes are also doing the opposite of what they're supposed to do ie: brushing an adjustment effect on rather than off and vice versa. Also, if I make changes to a layer, the changes don't take effect unless I turn off and turn on another layer. There are several other glitches that started at the same time such as actions I've used for years suddenly not working, or effects randomly appearing and disappearing on the screen.  I thought it may be my drawing tablet, but it happens when I try to use a mouse as well. I use the program for my work so this problem is really causing me headaches. It feels like something has gone fundamentally wrong with my PS and I'm not sure how to rectify it. I'm working on a desktop PC with a Huion drawing tablet.

Has anyone else experienced something like this and does anyone have any advice as to what I can do to get my trusty, reliable Photoshop back?

[alhashem1812]

Same problem here. Photoshop is unusable now!! everystep I take, I have to turn on and off layers