Impossible to know without seeing your blendspace and ABP if it’s being used.
It’s probable that your blendspace has not been adjusted to account for speeds higher than the default (which is 100).
it assumes that 100 is max speed, and is therefor blending straight to your sprint anim.
Again, if I could see screenshots of the landing page of the BS I would have a better idea.
make sure the axis value is set correctly, and LMK, you will likely need to replace the Keys after you change it.