I've been having this weird glitch with Clip Studio Paint EX Ver. 2.0.6 lately. Everytime I use a shortcut key for one of the tools, this strange brush circle appears where the appropriate one is supposed to be. To visualize the problem, I've uploaded a YouTube video as a demonstration: https://www.youtube.com/watch?v=jj-25dZDbzU

The video contains footage from my screen when I was trying to switch tools. Note that I was never just pressing a key once. I tried pressing "P" twice to get to "Pencil" instead of "Pen," but I was stuck on pen until moving the mouse. You might also notice how there was a circle instead of the gradient or paint-bucket icons on my mouse, even though those were the tools that were selected in the toolbar. Again, this lasted until I moved the mouse. The only button that was still working properly was "X" for switching the selected color. I don't know what could've caused this glitch and I would love for things to go back to normal.