https://www.gamespot.com/articles/call-of-duty-ww2-update-makes-hq-work-properly-fin/1100-6455275/

A new update is out now for Call of Duty: WWII. Arguably the biggest part of it is that it makes the Headquarters social space work as intended. Immediately after launch, developer Sledgehammer Games made HQ a solo experience to help alleviate server stress issues, but with this update installed, you should expect to see other players there.

HQ being a solo experience was a big bummer because it meant that you couldn't easily compete in the 1v1 mode or earn rewards for doing things with other soldiers like opening loot boxes in front of them. Under the previous setup, you had to manually invite people to join your HQ session to do these things, but of course that was not ideal.