You do not have any clue whatsoever about that

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This happens only for level 5 and 6 trade buildings, and it is hardly an issue. And yes, I am entirely entitled to have my own view

...
I hardly have any issue with that when I play vanilla. As for modded games, I can understand that many buildings giving modifiers can result in a weird picture, but then that is an issue which is particularly happening with that mod. Yes, I have many manufactures and post offices, but I hardly consider this even a glitch... And I am also entitled to consider that folks complaining about this mostly feel like bragging about how large their empire is, as it gives them a good opportunity to post yet another pic of their gigantic empire.