N/A Propane not filling

I just got an AAP-01 and a propane adapter and I tried to fill up the mag but it only shoots a couple times and then fizzles gas out of the barrel. I am filling it with the mag upside down. The propane bottle is cold and the mag is warm. Does this have anything to do with it?

Propane adapter? I had to look this one up. "The AAP-01 Assassin is the first gas blowback Airsoft pistol from Action Army Company...Uses TM g-spec compatible green gas magazine." https://www.evike.com/products/22699/
Is this considered an airgun?
 
Yeah - that's all airsoft stuff. I suppose it's technically and airgun, but not much convo her on AGN about them and convo is usually more focused around gameplay and the "tacticool" aspect fo gun setups.

To the OP - you may need to bleed the air out of the magazine. Try to hold the valve open for a second when you start the fill and then let it close. Also - are you filling from a propane bottle or a can of green gas? You may want to try a can of green gas if that's the case to see if it works better.

I think you get some better responses if you posted up you question here: https://www.reddit.com/r/airsoft/