What I believe is the core issue (although not-understood as to why) was my logic chain followed as such:
Tick()
{
AddGravity()
CalculateVelocity()
ClearAcceleration()
}
AddGravity() used AddAcceleration() downwards (or whatever direction gravity is currently at) every tick, CalculateVelocity() added up every Array Entry inside a TArray called Acceleration, then applied it to Velocity (with time modifications). After that, the frame would clear the Acceleration and the chain would repeat.
So adding to, adding up, and clearing a dynamic FVector array every frame things were getting jumpled. Yet, only when I used the OnScreenDebugMessage call. As DisplayAll showed everything working fine as far as I could tell.
The logic is still the same, however Acceleration is no longer an Array and just a single FVector. I’m going to hold off on marking this answered for a few days to see if it begins to crop up again.