Minecart will stop randomly

I have a collection system in my pumpkin farm that relies on a cart with hopper circling a tight curve, I think the curve must be the issue since another similar collection system never stops and it doesn't rely on a curve. The system seems to randomly stop at intervals of 2-4 days.

 

UPDATE:  I changed the system to avoid the curve but got the same result somehow, so maybe it's the parallel tracks?

additional info: I'm almost sure I didn't leave the loaded chunks but I never seem to catch them stopping, but I distinctly saw them working and they stopped within my playthrough, I didn't leave the overworld either

Also although the carts weren't in synch they stopped at the same two parallel points in the track, weird?