FC Promotion Bug: Promotion instead Causes Promotee to Swap Ranks with Promoter

An in game friend is taking an extended break from the game. They were our primary gardener and had their own rank with gardening privliges. I removed this rank, which knocked them down to rank 1. I then tried to promote them to a different rank, carefully selecting it, another gardener rank, from the menu. I then went to create a new rank, only to find that all of my priviliges were gone because I had been moved to the bottom rank and he had been promoted to FC leader... I am 100% certain that I chose the correct ranks. Furthermore, the standard prompt you get when you try to promote someone to the leader rank did NOT appear. The swap just happened randomly.

This is obviously a major issue. I'm fortunate that this person is a) an in game friend and b) away from the game. Unfortunately I have no way to contact them to fix this and, being the weekend right now, no way to contact SE support. The potential for drama is catastrophic with this bug as any time the FC leader tries to promote someone there's a chance you'll be switched with them, giving them the ability to sell the house/plot, rip up the gardens, kick everyone out, and empty the chest.