How can I play from my account in a world my friend sent me?

My friend and I are playing in the same world, but he can only play in the evening, and I want to play more often. So he sent me the world file so I can play.

But when I join, I spawn in his body with his items and race (we are using the Origins mod).

I tried joining from two different accounts, but I still spawn as the same player. I also tried deleting player data from the world folder, but it didn’t help.

I noticed that after each restart the world rolls back a bit, but I didn’t pay much attention because the changes were small.

Any ideas how to fix this?