Vending Machine scrap overflow - US Pure

A player bought a car key from a vending machine for 3,500 scrap. 1,700 scrap fell on the ground and 1,800 scrap was collected inside the vending machine.

When I tried to duplicate it all the scrap went inside fine.

The 3rd time it happened again this time 1,900 fell to the outside and 1,600 was collected by the machine.

I Have only been able to replicate it with car keys and not other items. It doesn't always happen every time but has been able to re replicated 3x so far with amounts between 2,000 and 4,500 scrap. 

The vending machine had nothing other than the 1 car key so there was ample room for all scrap to be collected.

I was unable to replicate it with a vending machine having different items in it.

Both vending machines had only a singular key in to sell a modular car at separate locations owned by different players.

I was only able to replicate the scrap popping out the backside of the vending machine at another players base selling a car key.