adding a topic to a third forum

When I try to add this thread https://permies.com/t/92625/root-crops/growing-dahlias-eat
to a third forum 'seeds and breeding' I get the following notice.

It was in 'roots' already and I had just added it to 'flowers' so 'seeds' would only be the third forum.

Looks like it's related to total number of forums it's been in, not current number of forums.

At least that's my guess

I guess that would make sense if it was originally in 'plants' and then removed from that when the new 'roots' forum was formed and then today I added it to the 'flowers' forum.
Then, maybe I had already added it to 'seeds and breeding' a while back, and then for some reason it was removed?  That would then add up to four...I think.

Does that mean it's impossible to add to 'seeds and breeding'?


Thank you!