The issue there is I'm using nostr.wine's filter relay to pick up free relay messages from followers who might try to message me that way. Unfortunately it also picks up NIP-28 messages that you're a part of. That's why I ended up leaving the group messages because I was also picking up that spam. Now I'm not a part of any group messages but still getting messages from the Amethyst group in global even though I'm not a part of it. That's probably what's most confusing to me.
Discussion
Click "People" icon in filter.nostr.wine relay setting make it disabled. You can solve like this. I dont see spam channel message anymore.
I think this is confusing because the two only active Public chats are Nostr and Amethyst. So, it feels like Global has a bug. But Global will show you any new message of any public chat channel, subscribed or not. The idea is to find new public chat groups to join. But if a given group chat has the most amount of messages, it can take over global posts for sure.
That makes a lot more sense! I was just expecting it to only public chats that I was a part of and not all public chats.