Mount speed can go negative due to weight

[Ostentatio 1,971]

Situation: Riding an aged bull (no visible traits at 36 Animal Husbandry) while carrying 263.116kg total weight, mostly dirt.

 

Expected behavior: Bull moves slowly due to weight, or possibly not at all.

 

Actual behavior: Sometimes bull doesn't move at all, but sometimes he seems to move with negative velocity. For example, pressing 'w' (move forward) causes it to walk backward at 0.71 km/h, and pressing 's' (move backward) causes it to move forward at 0.17 km/h.

 

Steps to reproduce: Carry a lot of weight and ride an aged bull. Not sure what weight ranges exactly cause this, or which animals it may apply to.

[Ostentatio 1,971]

Confirmed it also happens on a no-trait wild venerable horse.