Trucks only deposit half their amount into the Ore Sorting Plant

Issue description

This only seems to happen once I upgraded to trucks (pickups were fine). When the trucks drop off the iron ore, the amount that appears into the Ore Sorting Plant is consistently half the value, rounded down.
Here is an example truck with 22 iron ore.

After drop-off here is the UI of the Ore Sorter.

Just to be sure, I counted each ore on the belt out of the sorter to be sure, and it was 11.
I repeated this 4 or 5 times to make sure it wasn't a display problem, and the ore was actually halved.
I have tried this with copper to the same results.

Reproduction steps

Drop off Iron/Copper (perhaps others) into a new Ore Sorting Plant.
Observe the amount in it be half the amount that was in the truck.

Game version and build number

v0.6.3a (b333)

Operating system

Windows

I realize I didn't include the truck contents in the first screenshot. Here it is again, a different truck with it's contents before...

And after dumping...

29/2 floored = 14 ore in the hopper

I cannot seem to reproduce this locally. Can you please attach a save file where this occurs? Also are you sure the ore is not just immediately consumed by the sorter for processing?