Encountered a bug where when I loaded into a saved MP game, I spawned in the water and none of the units I had were attached to me anymore (not a huge deal) and oddly nothing showed up in the supports menu. Respawning didn't fix the supports(despite the fact it "should" since the menu option for the supports gets re-added when you click the respawn). I have as of yet not been able to replicate it, so it could have been some weird one off.