I haven’t seen anyone else talking about this, but I’m still unsure as to what happened, so I’m unsure if I can even recreate it. So instead, I’ll not everything that seemed off and everything that happened right before my friend died.

Me and my friend were playing multiplayer. Me on PC and them on Xbox One. I was hosting the world on PC and noticed before-hand that I didn’t see a single person on my Microsoft friend’s list.
I’m not sure if this was the first sign or not, but I had to go to the Xbox app and invite him manually.

We were exploring the Nether looking for a fortress when we found a Bastion? I think that!s what it’s called? Lots of Piglins. As we start exploring the bastion, my friend blocked up some Lava on a lower level. 10 minutes pass by before we get back down to where that is. He walked through where the lava had been 10 minutes prior and suddenly burst into flame.
He wasn’t taking normal fire damage either. Normal fire damage goes out after a few seconds and doesn’t do damage as often as being in lava does.

When he died, it said he died trying to swim in lava and all his items were destroyed. Nothing was there on my screen and I’m unsure if anyone else has had this happen.

EDIT: It’s been 4 days and I have not seen any staff comment on this issue. Even a,
“It will take us some time to look into this. Thank you for reporting” would be enough. At the moment, I don’t even know if they’ve looked at this problem.