Buy Now Button Disappers

[meccabooks]

I am having a serious issue, I have tried what ever I could think of and I am unable to resolve it.

 

I am using a third party software to manage my inventory, that software connects to Prestashop via API and updated my inventory, as I sell between other channels as well.

 

Everything works great, until my product goes out of stock, once my product goes out of stock "Add to Cart" button disappears, however when the software updates the qty's to above Zero, even though "Notify Me when available" disappears, which shows that it is recognizing that the item is in stock, but "Buy Now" button does not show.

 

I initially thought it was caching issue, and I tried everything but nothing works.

 

Does any one else has similar issues? or seen anything like this?