If it's a matter of TOO MUCH air puffing from the trigger, it means there's an internal leak that's only occurring when the marker fires. Essentially the only way to diagnose that type of thing is to swap parts until the issue is eliminated, since it's tricky to diagnose things that only show up some of the time.
In this case the two spots to check would be the bolt tip's seal, which depends on the type of bolt. The factory bolts use a molded rubber tip which is supposed to seal with the front of the barrel during firing. It may have worn out or otherwise needs replacing. However if there's an aftermarket bolt (of which there are about a half dozen) you'll have to track down whatever the manufacturer uses for a tip seal. Some use just a standard o-ring, which is easy to get, but others may use a proprietary seal that you could only get from the manufacturer.
The other possible cause would be the bolt's two outer o-rings. Those are standard size o-rings so you could try replacing them with new ones. The factory bolt uses a pair of 17/70 o-rings, although again some aftermarket bolts uses different ones.
Although having said all that, I would reiterate that if you can't notice an actual quantifiable decrease in performance then the problem would really be something to ignore. If you're getting like 300 less shots per air fill because of the issue then I would want to fix it myself as well. But if there's no adverse issues caused by the air burst then there's really nothing to bother with. Like I said there will always be a puff of air at that location even under normal conditions, so it may be something to live with. if you're unable to find any reason to care about it in the end