If the trigger has tension, then the front chamber is probably full of high pressure air. If it won't fire, then it could either be a stuck bolt or maybe your sear isn't releasing the bolt. Bolt stick is a level 10 tuning issue. The sear not releasing is a trigger rod length issue. The trigger rod should have a tiny gap between it and the back of the trigger when it is held against the safety with the gun gassed up and sear in the fully reset position.
Is your level 10 properly tuned? That is the most likely cause of your issue.
The valves can hold air. Usually, you can hold the trigger in and allow the bolt to release air as you are pulling the valve out the back of the body.
Except for the Automag in front, its usually the man behind the equipment that counts.