Just to understand

[Dorabella]

The strangest thing happened to me, never happened before. Not to be considered a problem but, just a curiosity
For no apparent reason, my PG's speed of movement/action increased considerably, to the point that I had to make my PG walk in order for the follower to keep up the running pace.

 

Spoiler

 

The effect was activated during the exploration of Bleackreach , Serana's mission + Crimson Nirnroot . Collected the last scrolls (Mzark Tower) , collected the 30 Crimson Nirnroot ,

the effect remained active until I delivered the scrolls and left Fort Dawnguard .

I checked the status of my PG and, no active speed-related effect appears . I did not use any kind of console code (I know there is one) . 

 

Spoiler

 

As I said, left Strong Dawnguard , the effect wore off .
I thought it was related to the summoning of the Soul Mound Dragon , but , I had summoned it in Fort Dawnguard , while the effect activated in Bleackreach

 

The only mod that could give me this advantage is the Skyrim Improved( SurvivalistIngenuity), but after a thorough perk analysis, there is nothing related to speed . Same for GreenTea

 

I was wondering : 
Is it an effect that is triggered randomly?

Has this happened to anyone yet?

Although I don't seem to have anything that conditions the speed: is there any mod that activates it?