So I tried to use a GBB pistol with green gas mags on a hot day and for some reason they just expelled the gas and didn’t cycle.
Unsure if this is a magazine failure or just the variance in temperature.
Think it might be a failure, to my understanding of GBB’s green gas should work better on warmer days, first thing that pops to mind is the O-rings might be dry and sticking open, or an oring has broken somewhere.
Hmm… ok I’ll double check the seals. Was doing a regular check when this happened 
Does it do it every time? I have seen them just dump for no apparent reason but then be fine.
And does it only do it in the blaster or even when outside? Like put a quick burst of gas in it and tap the valve and see if it still dumps.
If it doesn’t dump outside the blaster than something inside the blaster is causing it to hold the valve.
i am running low on green gas oh boy.
maybe a week ago it was fine and i don’t see any obvious failure. I also did recently swap out the lower frame but i doubt it has anything to do with it.
If you can give more specific details about your blasters make/model/brand of gels/gas etc, then people here will be able to give you much better information to help you out 
It’s not uncommon for certain brands of magazines to have factory gas leak issues, which can be rectified with a bit of fine tuning, along with the technical details of setting, lubricating and gas filling of whatever brand GBB that you are using.
mags are DB G17 + 1 poseidon orion. Slide is a DB G19, the frame is from a poseidon orion 3
hammer housing is DB. so mostly a custom DB glock with DB BBU. I actually don’t think that helps considering there’s probably a lot of points of failure.
Suffice to say it’s still at its core a DB glock.
I can’t comment much because I only ever had experience with a single FB GLOCK G18C GBB Pistol, but I did get to learn the importance of the gas valve fitted in the magazines, which had to be adjusted and lubricated just right to function properly.
The strength of the hammer strike on the gas valve was very important as well.
Lubrication of the gas valve, nozzle slide seals etc were also very important.
Many models of GBB mags were renowned for leaking gas from the actual magazine joint seals themselves, but your issues seem to be totally related to the pressure of the gas valve and the hammer in cycling properly.
Lubricate the crap out of the valve, maybe experiment with the height/clearance between the valve and hammer mechanism, try out different types of gasses for both hot and cold weather performance and see what works best in your own particular circumstances