Order stuck as unfulfilled (but 'Unfulfilled items' section is gone)

[bbonczek]

If I use:

 const orderService: IOrderModuleService = container.resolve("order");
 orderService.registerFulfillment({
   order_id: id,
   items: [{ id: orderItemId, quantity: 1 }],
 });

for an order with just one product I'd expect that this order gets fulfilled status. What happens instead is that the order remains Not fulfilled but there are no 'Unfulfilled items' section.

I tried to combine my code with registerShipment and registerDelivery as well which had no effect. Is it a bug, or am I missing something?

More details here.