Your fill tool has a '-2' pen set for the background default pen.
I don't know where a '-2' pen comes from.
But if you set your default fill tool to the background pen colour (-1) then all future fills will be fine.
Any existing fills you will have to amend as well.
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11