Hi, I'm still relatively new to D&D beyond so this issue may just be something I am unaware of but nonetheless I am unable to find a solution to the problem either through my own perusal of the Beyond or through google searches. Basically I bought all of the books a few months back to host campaigns for a discord server and I do have some homebrew things added to my collection and they automatically show up in the character creation in the campaign. however I recently became aware of multiple homebrew races available in character creation in my campaigns that are not ones present or have ever been present in my homebrew collection? my question is how did they get added and how can i remove them?

All homebrewed content in everybody’s collections are automatically shared with everyone in campaigns with that person. Most likely one or more of your players has those homebrews in their collection.

Okay awesome I was not aware of this thank you guys for clarifying this for me.