Procedurally generated spline mesh actors are “Weaved” together to make this track… .anytime the physics ball hits one of the “seams” which doesn’t show any collision as seen in the video it jumps… what gives? please help!
Does it only jump when it’s on the spline mesh, or is it jumping on landscapes/static meshes as well?
Your colliders are touching at 0 distance right? Try to overlap them a little bit and say how it went.
I know this is not a fix but I suspect rounding errors as the physics engine cuts a lot of corners when calculating.
Also try tinkering with the physics engine sub-steps. Try wildly higher or lower values and see if changes anything.
I am experiencing the exact same issue with my cars physics
We got the same issue on one car project:
When the car scrapes the colliders on the side of the road and moves from one collision plane to the other it would occasionally be launched in low earth orbit. 
I think the solution we used was to sweep the car collider get the hit position and move the car to that location before the physics kick in.
It was on in-house engine though, not UE.
I fixed this with a solution from BoredEngineer on Discord (Unreal Slackers)
These settings below fixed the issues and made it playable: I only touched min and max contact and multiplier…
i did try messing with substepping and setting it to max (16) to no avail… the solution below that resolve my issue (the one messing with the simulation settings)
overlapping the meshes did not resolve it, the collision still occurred whenever the overlap occured regardless of it being closer or further away(as soon as collision is on the next mesh it jumps)
static meshes as well… i tried adding a bunch of cubes in a straight line and anytime the ball overlapped the next cube it jumped