Which is a bit confusing and undesirable. Looks like Lemmy creates a board for fedi groups and uses the first group mentioned as the destination for the post, rather than any subsequent groups mentioned... it's extremely weird and confusing. Anyone got any insights/thoughts on this behaviour?
Lemmy will only use the first tag in your post. This is to prevent spamming.
Any other tags, such as users etc, will still work fine.
I don't think lemmy created that "board"("community" in lemmy lingo) just because of your post. I think it recognised or had already recognised the spurs group and tried to synchronise with it after your post like it would with any other group/community. I'm not sure how well generic groups work with lemmy right now though.