Can't Sprint on Mount

For a little over a week now, I've been experiencing issues with the sprint function while on mounts. My character can sprint perfectly fine until I mount a boat or horse. I expected the problem to remedy itself, but it hasn't. I can't find information about anyone else having the same problem. I have tried resetting my sprint button, restarting the game, restarting my computer, and sprinting before mounting. Nothing has worked so far.