I'd like to revise my last post when i said "A "vacuum" is the only way to keep it flowing "consistently".
What i meant to say is "a respectable amount of negative pressure (sucking with a tight airflow) is the only way to keep it flowing "consistently".
I'm an idiot and i wasn't concentrating on what i was writing.
I saw your answer and agree. Heat is what it's all about. If it builds up too much for amount of wicking and /or air supplied, the process collapses. I try not to drain my tanks evan. I do, I really do.
Again as counterintuitive as this may seem (for a beginner) I've gone almost exclusively to very wide bore DT's…even as I sometimes still vape <20W from time to time. I find that by lip blocking the DT I can simulate tight draw on the fly as the device and conditions (or mood) requires it. It was like a revelation one day…why am I sticking to this monotone commitment to airflow. A/F rings are grand but often hard to adjust and more suitable to calibrating the center or what's favored for the atty. But for many of us lip blocking and sideslip came naturally smoking. And it just works. So tight draw, yep. Straw draw, nope. Somewhere in there tho.
Just to give some encouragement to the OP. It's a physical world. Things go badly. Observation is key. We try something else. Moving on sometimes is unavoidable.
Good luck.