Wait, just so I’m understanding, the dock works with the LG TV if you connect your laptop or Surface Pro, but not your Steam Deck? If so, it sounds like there’s either a setting on your Steam Deck that needs to be changed or the Deck itself is faulty.
Does the Deck work with other HDMI monitors?
Yes, your OpenStreetMap username. Does not need to be something truly related to you, in fact since most of your edits are likely to be near where you live or work I would strongly recommend they not be something related to you or any usernames you would normally use online.