Hi there - I am having what I think is a similar issue? I posted about it here:
Long story short, I just started the game/a campaign for the very first time a few days ago with a seasonal character. Now I can’t even play the campaign from where I left off. I can’t play that character at all anywhere (note I am not a Nintendo Switch online member).
Is this by design or the result of a bug? Hard to find a straight answer anywhere.