In a blendspace each animation has its own blend time and blend mode you can choose from.
Try something other than linear.
We still have absolutely no idea what it is you are even attempting to do being that you didn’t really explain it, and you are not doing what everyone else has done always for a jump.
Further, you say “jump” and then show us a running 1d blend space (Which is actually also likely incorrect for the simple fact it does not appear to be 1d when it really probably should be.)
If you want help or a solution, maybe try to actually detail your issue enough for people to help…
Screenshots, or videos of the issue happening would probably help.
But are also completely useless without your setup if you aren’t going by standards.