A frame that has artifacts that came from the previous frame

[LightingBasket4959]

There are artifacts in a frame on a white background that were left over from the previous frame that also had a light background.
Command used: gifski --fps 3 --repeat -1 --quality 100 -o test.gif *.png

Example:

You might need to zoom in to see it, if you don't see it I changed the brightness and contrast so you can see it better.

Here are the original frames before conversion into a gif:
test2.zip

[LightingBasket4959]

This is a duplicate of #143, I guess, but this same bug seemed to creep back up sometime after 1.4.0. By the way, please let me know if you need more info.