I encountered a random bug.
I bought a van and drove into the warehouse. The van was assigned to slot #2. This annoyed me because slot #1 should be filled first, so I maneuvered the van into spot #1 without leaving the warehouse.
This worked fine for deliveries until I tried to buy another van and assign it to slot #2. The warehouse entry doors both read as occupied.
I was able to fix it by going inside the warehouse, driving the original van out of the warehouse, and then back inside properly through the correct door. Then I was able to drive the second van in as well. Now both vans are assigned properly.
I was going to recreate the bug to confirm…but now I cannot drive either van at all (I cannot enter them from inside the warehouse anymore).