Problem with Photoshop tools

When I use some tools in Photoshop, something strange happens. Here's a screenshot when I use the "Spot healing brush tool". I try to remove the road and i drag it in the direction of the green arrow. When I reelese the mousebutton it automatically draw up and to the left like the red arrow shows.
Why doe's it do so? I have PS version 21.1.0 on a Windows computer, and latest graphiccard drives. The fun part is that it works OK with my wacom pencil but not the mouse.