Blue building icons

[Jtgaag]

Hi developers,

When playing the game (second level) after ~30 days the buildings in the menu in the second row, first column turned blue. For the quarry it looks like the advanced quarry and the others just turned blue (never seen those assets in the game)

The following link has 4 images of the bug.
https://drive.google.com/drive/folders/1ds9qjcH7XvIgBI2S2pErbWXMeqxqtwhn?usp=sharing

Cheers,
J