You can send it my way; depending on the bug I might be able to help (or at least make sure we have it documented) but if it is account related I won't really be able to help and a ticket is what you will need to use.

I pinged the internal group about it so they can dive into it; but I don't have any immediate suggestions to fix it unfortunately.

This is the first I have seen this specific problem personally.

Generally being kicked to lobby is your connection to the server instance dropped. This is often due to instability on the players end; but what is weird is you get kicked nearly instantly and are able to nearly instantly rejoin. Timing out should take longer, and if you were unstable it doesn't look like it.

But thats me speculating, people with a lot more ability to dive into it will be able to figure out more.

Looking into what our server is kicking back - I'm wondering if you're playing from a college campus wifi, or something similar?

Wondering if you can take your steam deck somewhere else and see if it fixes the issue for you. (and if you're on a campus, this would mean one not on campus) Currently it looks like the server is giving an error specifically with your requests that imply there's something at the network level especially because it's happening on both steam deck and xbox which are on different client versions.