When the minister visits the warehouse, the upgrade discount only works in this building.

[Delfador]

When the minister visits the warehouse, the upgrade discount only works in this building. In exactly the same building but without minister inside, the discount is not displayed, although in theory, while the minister is in the one type of building, a discount of this type should be displayed in all buildings of this type.

[Obelix]

I would not consider above described situation as a bug, but as a feature. I recommend to discuss this in the forum "Gameplay Discussion".

[Delfador]

14 hours ago, Obelix said:

I would not consider above described situation as a bug, but as a feature. I recommend to discuss this in the forum "Gameplay Discussion".

That is, I need to keep a minister in all four sawmills in order to carry out technologies at a bargain price right away? It's stupid and inconvenient.

[Gurken Khan]

42 minutes ago, Delfador said:

That is, I need to keep a minister in all four sawmills in order to carry out technologies at a bargain price right away? It's stupid and inconvenient.

How stupid and inconvenient it is depends on how you handle it.

Personally once I have the ministry I keep my ministers mostly inside for the trickle for a while, except for certain research projects; I try to build those research buildings nearby, like a tower, a temple, a fortress.