If I leave the game open without interacting with the pc at all for an hour-ish or longer it replays the events that occurred, even players moving, leaving, and joining the game, at a fast speed and you can't leave the game or do anything during this other than laggily walk around.

Steps to reproduce:
1. leave Minecraft inactive for an hour.
2. start playing Minecraft.

Expected results:
Everything works as normal.

Observed results:
Time-lapse of all events that occurred after going inactive. Shown below in the video.

Edit:
It usually happens on my pc, but I have had it happen on my Xbox One X a year or so ago.