Enterprise profit

what would cause my enterprise profit to drop suddenly one month and continue at the lower level? Built many corps in one resource and they were consistently making around 2B profit each month and suddenly after one month its more like 0.5B for each corp..resource is still in low supply/high demand and I don't see a change in the price of the product by looking at the price chart but I'm guessing that's it??

well i see one month my total turnover for the enterprise dropped drastically too

Unfortunatelly we have no idea where it is, name of the enterprise, names of corporations and world name.

maybe already too late now to check.