Around the map, and I haven't been able to figure out the "why" (recently placed structures/player online/etc) structure and deployables are only showing the Steam ID for owner. I checked a build I did, my name showed. Out at our event build, I see some blocks with @jacktapper's steam id, but I see @Dicko A La Mode's player name on blocks and deployables he placed.
I found a small water catcher randomly by the road, only showed steam id. I removed it, then placed my own and then my player name shows.