What I expected to happen was...:
The allay should get dragged along with the player when on a lead and should follow the player who gave an item to the allay wherever the player goes.

What actually happened was...:
The allay flies off aimlessly and neither follows the player even if an item is given to the allay by the player nor gets dragged along when a lead is attached to the allay.

Steps to Reproduce:

1. attach a lead to an allay and tie the allay to a jungle fence
2. start a song in a jukebox
3. go to the nether
4. come back from the nether after about a minute
5. the allays break free from the leads and do not come back even when a lead is reattached to them by the player.