Problem with drawing on tile layers

sooo my brush is doing some really weird stuff

only happens on tile layers and sometimes it does that after a couple of hours of drawing, and sometimes its like that from the start. its literally impossible work with.
seems like it drags pixels from neighboring tiles. tile layer is in “modify existing tiles” mode.

im using 1.3 steam version

this is a bit of canvas, just to show what neighbors the tile in the gif