Hey,
This has happened to me a few times so I figured I’d toss it on here–whenever someone joins my on-going forge lobby, either a new round starts or a black screen appears. When I’m in control again, I’ve lost all progress since I last saved. It’s pretty annoying but luckily I haven’t lost too much.
Thanks.
EDIT: After I came back to the map, the objects I had placed before the round restart as well as the ones after the restart were all there. Still not a catastrophic, but it’s a bug none the less.