When I play online, like on cubecraft ect., It will not show what I typed in the public chat.

When I type on the public chat online while not display to other players in the lobbies or games. I play my sister in cubecraft, Me on xbox and she plays on the switch. I type something on the chat and she says she can't see it, I even checked myself to see if it wasn't a joke, it will not show what I posted at all. I haven't posted anything inappropriate in the chat to get myself banned, and even if I did something that was seen as inappropriate, I was never advised. I want not only talk to my sister but my friends online, and during this time we all need friends to talk to. I hope this issue could be resolved as soon as possible.