Apparently, we're all on the same boat. 1 open slot as well. Notify me in this thread.
Granted the raid boss I posted wasn't a Seed Bearer, it was Level 80 which was equally difficult for me to find nowadays, and it was shared to allies to help them finish RB quests. Some "random" with a maxed rainbow helper squad on my list one-shotted it when I was about to get a point off regen to use on it. That was the last straw, after three passes.