API returning null:null:null

[JulesGresset]

Describe the bug
In some conditions, the route kpi/averageTimeAllDishes returns null:null:null

To Reproduce
The conditions to reproduce the bug are not clear.
During the PGE3 test phase, the bug appeared with the API call https://api.hellokitchen.fr/api/3/kpi/averageTimeAllDishes?timeBegin=2025-09-10T08:04:36.711Z&timeEnd=2025-09-10T09:04:36.711Z&breakdown=true in the KDS but since then, the orders made this day has been deleted.
Seems to be linked when there's one order marked as ready but when the food inside are not individually marked as ready.

Expected behavior
The API should return the average preparation time of all dishes