Sorry to hear that you are having problems. I am new to the platform and can't help with the filling to 80bar. I can't think of anything that would keep it from filling? How are you trying to fill? Are you using a hand pump, compressor, tank? Are you new to PCP's or experienced?
As far as the puff of air from the breach it sounds like the o-ring is missing or damaged just inside the barrel where the probe inserts. It's an easy fix if you have the tools and minor skills.
I'm assuming you bought it new and still under warranty. If so, and the vendor is refusing to take care of you please share so the rest of us can avoid doing business with them.
It took me a while to figure out that RTIarms.shop is a dealer in Spain. RTIarms.eu is the manufacturer in Europe. I'm sure RTIarms.eu will help out if the dealer is refusing to.
With more info other members can help with the issue as well.