Crown FX Fast Airleak through Barrel

I have been using my Crown FX .25 successfully over the past few weeks (new) and just shot two pellets tonight when the air started to leak through the barrel.

I know my tank was almost full (about 200BAR) as I have a Compressor to fill it regularly. All the air leaked out actually and left the tank and barrel very cold.

I searched the site and found a similar problem so I removed the tank and reconnected…Set to cocked (without magazine) and started to pump. The air is still coming straight out of the barrel and not filling the tank!

I have sent off a support ticket to FX Airguns but haven't received a reply yet so hoping that someone can shed light on this problem.
 
I'd pull the valve and valve seat and inspect. Normally I could fire my gun (any pcp) and it would fix this issue.

I've spoken to FX Importers in Australia (Hermanns Firearms) and they are sending me a new valve seat and O-ring set. Some of the FX Crowns have slivers of steel from milling which is cutting the O-Ring in the valve seat, I haven't pulled it apart yet but I suspect they are right in this instance. Thanks for the advice though.