Runescape player offline slayer

I tried to do some slayer with my partner and it kept saying “That player is offline” and he got the same message when he tried to invite me, before the new interface for Java came out I had the same problem but only when I tried to invite him, I’m not sure if i’m the only one getting this issue or if anyone else is or knows how to sort it, or even if a Jmod can notice this issue, because I enjoy slaying with my partner!

So hopefully, someone can sort this.

Edit: Both our chats are ON!