Correct, this is how it's intended to work, because having the pathfinding algorithm check all the same stuff that precise cell-wise movement checks is generally not desirable, so they don't always behave the same (in more than just this way; same with keyboard-based running movement as well, though to a lesser extent--each have some of their own quirks).
You can still mouse-move over stasis traps on treads normally, but you're going to need to do it manually.
I'll look into adding this check and see how expensive it will be, though.