Player Disappeared

Hello everyone 

I recently had a gold rare Donnarumma in my transfer list. I checked compare price, and decided to sell mine at equal to the current (at the time) lowest price. But when I tried to confirm the listing, it said my action had failed. After multiple attempts, I realized that it was now saying that I had successfully purchased the item for the price I was listing it for. This is on the app by the way. So after several more failed attempts to list the item at any price, I closed the app. When I reopened it, the item was completely gone, not even in quick sell recovery. I didn't receive the coins for a sale, just completely lost. Can someone please explain what went wrong here?

(Sorry for posting again, but my last attempt seems not to have been successful, just like the transfer.) 

All the best to everyone!