Repairs not deducting indicated amounts from shipyard/equipment dock

[Falcrack]

When I order ships to get repaired at my shipyards or equipment dock, it indicates it will cost a certain amount in hull parts and energy cells to repair it. But after watching the amounts in storage very closely before and after my ship is repaired, I notice that there is no deducting of wares at all for the repair to take place. It is completely free, in contrast to the amount indicated in the ship upgrade/repair screen. Should repair be free in X4 for repairs at your own stations, or should there be some cost in materials? I think there should be a material cost. Not sure if this is a bug or if it is by design, but I thought it worth pointing out.

[Buzz2005]

weird I don't remember ever seeing any cost to repair on npc or own yards, auxiliary ships also need 4 hull parts for "repairs" yet its always free even if you have none

[Imperial Good]

I think they are meant to be free to be consistent with the free self repair M and larger ships have. The costs being listed may be a bug.