If there is something wrong with the tank usually it's nothing you will be able to fix on your own. Most likely its something to do with the gas canister which is something a mechanic or dealer will need to fix. When you fill up your gas tank do you usually top it off as much as you can? That is usually when you start to see issues with the gas tank. If I find anything more concrete I will pass it along.

Yes I top it off as much as I can.