There seems to be a bug in the game when it comes to selling items. Once the value of the sold items reaches a certain amount, you get only less than half if what you should get. I think I have lost trillions this way. E.g. I sell 20 structs for a promised gain of say 60 billion but I only get 26 billion.

Have you an Auto-Upgrader active? Perhaps some of the money is just immediately spent to upgrade an Army Camp/Hospital/Mine.

I think Phoenix is right. That's what happens to me. I normally forget to turn off auto upgrade army camps when I sell tons of items. I'll expect to get x billion but in reality I get way less because it went ahead and upgraded my camps for me.

Edited 7/17/2021 21:12:23