Not really a problem, but an issue.

Later in the film they say Thanos killed Loki, Heimdall and *half* the Asgardians.

But the way that opening scene played out, it didn't seem like they took any captives at all. Basically everyone except Thor and The Hulk were dead.

Which would include both Korg and Valkyrie, since they were all on the same ship at the end of Ragnarok.

I'm sure the reason is there wasn't a place for those characters in the movie, and they didn't want to specifically kill them off.

But they even showed the devastated remains of the ship, with corpses floating around. Nobody survived that shit.

I wonder how they are going to explain how Korg and Valkyrie survived it. Unless the inevitable reset done in Avengers 4 is going to undo everything so that they don't need to worry about it.