Elite Camel Riders no longer move after loading save game

After loading a saved skirmish game playing the Abbasid Dynasty, Elite Camel Riders no longer move. They do pivot toward the direction they should be moving into but stay put.

I have consistently reproduced this with 8.2.218 by producing these units, saving the match, exiting the game, starting the game up again, and loading the save.

I had to abandon the save game for this reason.