Pausing the game should stop all entities from moving. When the pause screen is open, the entities do not appear to be moving, but their positions will update as soon as you unpause the game. To trigger the bug, simply spawn an entity, pause the game, and then unpause. It will have moved.
This is in singleplayer.
Linked issues
Comments 1
Duplicate of MC-34641 - If you have not, please use the search function in the future, to see if your bug has already been submitted. If you could not find the original report, please comment with the keywords you searched for.