I thought you might be interested in looking at 3dsmax: 2 UV channel problem (possible corrupt UVs :( ).
https://forums.bohemia.net/forums/topic/86909-3dsmax-2-uv-channel-problem-possible-corrupt-uvs/?do=findComment&comment=1480793
× Pasted as rich text. Restore formatting
Only 75 emoji are allowed.
× Your link has been automatically embedded. Display as a link instead
× Your previous content has been restored. Clear editor
× You cannot paste images directly. Upload or insert images from URL.