Yeah I guess it wasn't that bad. They didn't just ignore me after all. It felt really bad as I was writing that as it was fresh and the first time I've been made fun of in the game.
All of the chat was happening during the boss fight though. I have a keyboard hooked up to my PS4 to type with but I use the game pad to play. I don't even know what the chatbox etiquette is. Do people generally only talk at the start or end of the dungeon? I've often seen messages in the middle of fights so I just followed suit.