I was wrong. The o-rings were not the problem. It's the shell that has a leak! Surprise!
I laid the Phoenix down on a piece of paper overnight with the air hole at top. In the morning the paper was soaked in juice, about 2 1/2" diameter stain. I was able to blow bubbles when I inserted the lower end in water, covered the air hole with my finger and blew into the drip tip. I tried the same with a spare Phoenix and it was airtight at the pressure my lungs produce.
I looked at the shell under a magnifying glass and am not able to see where the leak might be.
In fairness to Phoenix, this is a clone from Discount Vapers. Not an original Phoenix.