Leashed happy Ghast can lag out a world

Having a happy Ghast nearby can randomly cause the world to lag when the Ghast is in simulation distance. In my case the Ghast was leashed to a fence, not wearing a harness in case that matters.

Result: World lags and becomes unplayable. Mobs will freeze in place, dropped items float in the air, unable to break or place blocks etc. Flying away from the Ghast until it’s not visible anymore will instantly fix the lag and the world runs fine again. I’ve had the Ghast roam around freely for a while and that did not cause any lag at all. Could be caused by pathfinding behaviour while leashed.