Saving and reloading the game makes them work again, but they don't stay that way.

 

Another issue, which probably has been reported already, hatchet type weapons (like the Hearth Harvest) have graphics scaling problems, the icons are way too big.

Yup, got both of those bugs in my playthrough as well. 

I found that removing the boots and putting them back on will reset the speed boost.

 

But it makes me a bit nervous about how many other item-based bonuses might be lost.  (Though this could be something specific to the combat auto-slow thing.)