This is why plumbers go to plumbin school, so we can be learned about gas and how to run it.
It's more than just sticking bamboo in the groundfor a pipe.
You need a card to buy the CSST. That goes into that bein' learned about plumbin' again.

I'm sure you have done all the gas goesinto's to see if you can even use what you are hooking up. It's a gas usage thing. Water flowing into a tub while the lav is also on and then someone flushes the toilet, water keeps coming out just at a very reduced rate. That's ok, it just takes longer to fill the toilet, tub, etc. With gas, it's a different story...

Hey, it's your place, have fun...