was hoping to get some more info on why 9V batteries are inadvisable.
Because they are expensive and very low current and capacity. That means they are limited in how long they will work or how much power they will provide. Technically they have what is called a high output impedance which exacerbates the sort of problems you are seeing.
What a lovely community.
We are, we give good advice here, and we consider no question is too simple or trivial to answer.
What we get irked at is having good advice argued with. You are the one with the problem. We tell you what to do to put it right and then you argue that it is not correct advice.
If you are so smart you would not have to ask the question in the first place as you would already be doing what we advise you to do.
There is a world of difference between someone who is ignorant, that means that they do not know stuff but want to learn, and a fool. It is fools I do not suffer gladly, the ignorant who want to learn are welcome.