Here’s my proof
Everyone have this collection buff.
Nothing wrong here.
Oh sorry it’s just weird they don’t appear tbh( in the collection)
I have seen this happen with various characters, they’re only officially in two collections, but have buffs from three collections.
I attributed it to the fact that one of their skills (shield or stun usually) links them to that collective skillset,
PB should really put a note in the buff that makes clear that it applies to all heroes. Posts like these pop up regularly.