error transcoding from H.264 to Quicktime Prores 442

When transcoding from 3840 x 2160 to 3840 x 3840 i get this error.  It won't fill the 1:1 frame but instead it takes the 16:9 format and shrinks it into a 1:1 frame.  I am also seeing this error coming from other companies that submit animation to my team.  So I know this is an issue that multiple teams and people are dealing with.