[KCD2] How do horse stats work?

I have a horse that says it should have 57 speed. And used this website to determine the best gear to increase speed. But no matter what (even if I have nothing equipped or on the horse at all) the highest it's speed goes to is like 36. I can see the horse should be significantly faster, and I know its not the gear/weight of inventory that's affecting the speed, so why would my horses speed be so low? All of the horses stats are shown in the red, but I have no clue why... Any help? Is there some other source of debuffs to the horse I could see?