I have selected “selection mode” as can be seen in the first Screenshot and when I select an area with the rectangular tool, it creates this pink area. I can’t remove this pink area with ctrl+z and I have to restart the software in order to get rid of this. Also, it creates tiles, so it’s not just a visual bug, it really changes my tiles.
Another thing is: I now created a tileset project with alpha transparency activated and when I try to fill an area with the fill tool + outline mode, it does this:
Firstly, it creates this pink background (second color from color palette) and secondly, it strangely only fills the tiles with gras on it, but not the empty tile in the middle. This only happens to me since I have changed this project to an project with alpha transparency.