Tripwire triggered by unmoving minecart loses power when it shouldn't

In a redstone build I was making, I stack 3 minecart-chests on top of eachother. I use a tripwire to verify that all 3 minecart-chests are in the correct spot. However, after disconnecting from the realm and coming back later, Some of the tripwires are no longer activated. These tripwires cannot be activated by a player passing through them either. The minecart-chest must be broken, and at that point the tripwire can be triggered regularly again.