Mr. Moore, are you a developer for Thunderbird? Just asking based on your "poke/fix" comment.
Even if you're not, if you beta test and report issues, not being able to use the Mozilla Apps Enhancement method to move columns is a big break from many past versions of Thunderbird, and likely the issue is on their end.
Brian - Windows 10 Pro, 64-Bit, Version 1909, Build 18363
Power is being told you're not loved and not being destroyed by it.