I'm not 100% sure if this is a bug. The conditions do not change, but the loot is synchronized at different speeds.
There are 1000 apples in the container (workbench), I log on to my test server (local) and the items in the workbench are synchronized with my client at different speeds. Every time I teleport out of my vault I leave the network bubble of the workbench.
The video shows that I connected to the server and the items synchronized almost instantly, but when I logged on to the server without restarting it, the synchronization speed dropped significantly to 10 items in a few seconds