Cannot delete or move songs from sub groups in the new songs group
The problem exists in the sub groups in the group “Archive\All songs\New”. In the parent group you can delete or remove the song from the list, but in the sub groups both options are not enabled, as they should be. This does that the song list in the new group cannot be edited though the sub groups.

The only way to work around this bug is to open the songs from the sub artist groups in the new songs group, and then make the list changes from here.