Let me be honest with you.
Prana is genuinely subtle, and not everyone is able to detect it initially.
The fact that you didn’t feel a difference between breathing through the nose and the mouth, or that you naturally returned to mouth breathing when given free choice is actually useful information — it suggests the primary pranic channel through the nose isn't yet open. That's something that can change with time and practice.
That's not a flaw — it simply means this is not the right course for where you are right now.
Rather than have you invest in something that may frustrate you, I'd rather point you toward other courses I teach where I know you'll thrive:
New to Meditation?
My Begin Meditating course will give you a firm foundation and help you quickly establish a practice that can last a lifetime.
Learn More about Begin Meditating
Have a Practice?
The course I teach on The Doorway Of The Midpoint will be the most rewarding next step for you in deepening your experience and skill.
Learn More about The Doorway of the Midpoint
The subtle body actually has to be opened up to some degree before it is able to detect prana. These courses I'm pointing you to will begin that process in a natural and effortless way.
Some people find that if they continue to use the exercise I just shared with you — watching with keen attention and complete focus to what the breath coming in through the nose feels like — prana sensitivity does begin to develop for them, so please come back to this as often as you like — or simply continue to try it on your own.
If you ever feel 'maybe I detect a little difference' then come take this course and I'll help you turn that new spark into a flame that's undeniable.