For the past several days I've observed a weird random speed variation is my character's speed when not on horseback (on foot). I've not noticed a direct pattern between action executed and the bug. How the bug plays out is that, for no apparent reason, character starts moving way faster than it should and what it is normal for it on normal circumnstances. It seems to affect sprinting, but I can't say it with absolute certainty.
Character is bosmer, which does have Hunter's Eye that grant's speed, but the passive is applied constantly, so there should not be any noticeable speed variation as the one observed.
It is a NB with bow usage, so it could be attributed to Hasty Retreat bow passive. However, the character moves still faster than with the 30% increase from Hasty Retreat and there is no animation (Hasty Retreats creates green glowy lines under the character's feet).
Hasty passive from the Fitness tree is at 8 points, which means a 2% increase in speed, but again, that should be applied constantly and the bug triggers randomly with the speed variation going from normal to way too fast.
Character has Steed's Blessing at 40 which I'm unsure whether it affects horses or not (don't think it does) but it is not slotted. It would still not explain the astounding increase in speed as it grants right now a 16% speed incresae, which is less than Hasty Retreat's increase, and yet the perceived speed is much faster than the latter.
It is not a gamebreaking glitch but it has made me fall off high places as the sudden burst of speed has made my character lierally fly off edges before I could take control of it.