Can Pulmonary Function Tests be conducted wrong or read wrong?

I had a Pulmonary Function test done last year. The doctor told me I had "light" "early onset" asthma. He said it was because my NO was a bit high (18 with 16 as upper limit). He said nothing else.

I tried an inhaler, both maintenance and acute. I think Symbicort and Albuterol. Neither helped me in any way.

Came back later and saw his NP. After a visit or two we found a few things: Anxiety meds helped my attacks, distraction by talking to people helped, but the nasal spray given to me by an allergist and the inhalers were simply not working. The allergist did a blood test and found no allergies though I was diagnosed with the pin prick test in another state as a child with seasonal allergies. That was 15 years prior and I was told that I basically grew out of the allergies and living in a vastly different climate with different allergens contributed to that. That said, an ENT did find swollen turbinates'.

All of the above led her to say I might not have an asthma problem and if I do per the PFT, it's pretty minimal.

The main culprit was thought to be Acid Reflux. I suffer from LPR (Silent Reflux), VCD (Vocal Cord Dysfunction), as well as severe anxiety which I have had for many years. Hence, the thought process was the LPR/VCD combined with anxiety was a bigger culprit.

Had a recent visit with a new NP because I had asked to check for E-asthma. To my surprise, it turns out they had checked for it previously, but now she said I had traditional asthma much more severe than the original Dr. and NP said!

I went today to pick up my medical records. Based on what is written, it does seem to indicate a moderate issue:

"The FVC, FEV1/FVC ratio and FEF25-75% are reduced indicating airway obstruction. The airway resistance is increased. The SVC is reduced but the TLC is within normal limits. Following administration of Bronchodilators, there is a slight response. The diffusing capacity is high for the measured volume.

Conclusions: Moderate airway obstruction is present. The lack of response to bronchodilators may indicate a refractory state. Prolonged use may be of benefit. The increased diffusing capacity would be consistent with asthma or a cardiovascular process such as left heart failure or shunting. "

So, my questions:

-Can the test give false positives?
-Can anxiety mess up the test results?
-Can LPR mimic asthma on a test like a PFT?
-How much room for interpretation is there between providers typically?

I am just very confused how the inhaler didn't help and the original Dr and his NP were both not too concerned but this new NP says there is a much bigger problem and it seems supported in the initial report. What am I missing?