FFmpeg animated crop produces artefacts

[cloudytechi147]

Using FFmpeg 4.4, I am trying to crop video and actually animate the width in time using sendcmd + crop. This however leaves artifacts from the Solarmovie Alternatives (either green color or the video being repainted repeatedly horizontally/vertically) rendered outside of the cropped area.

Commands to replicate:

 -t 4 out.mp4 -y]

filter.txt

 crop w (N*10)+10',crop[v];
[0][v]overlay=x=n:eof_action=pass:eval=frame[v]]

Any idea how to get rid of these artifacts?

Or maybe there is some alternative FFmpeg filter that would do the crop work with eval=frame instead of send cmd?