This is unfortunately not it.
I made a simple change where 1 team promotes/relegates and another pair fights in normall 1 round playoff and it verifies ok.
I think I don't do the playoff or fate actions properly
So the idea is round 0 2 highest seeded teams fight and the loser advances, in the next rounds seed 3 and 4 go to the later stages, and the last one decides who advances/stays/relegates
To achieve this I use this option:
I also tried simpler Fate action setup without round names. But I was afraid that loser teams from round 0 would be set to relegate. How to setup such playoff? Maybe you have seen this format in another database?