Halter led Animals becoming un-led when mounting a horse

[Muse 2,225]

This has happened several times today. I am leading a foal and use the same halter rope to lead my horse.  As soon as I mount my horse the foal immediately becomes un-led:

 

[07:12:34] You start leading the young Clipraid.

[07:12:53] You start leading the venerable fat Bouncerwar.

[07:12:55] You mount on the venerable fat Bouncerwar as the driver.

[07:12:55] You stop leading the young Clipraid.

[07:12:55] You stop leading the venerable fat Bouncerwar.

 

[Trash 192]

Sounds like the embark bug