Took my Infiniti to three different workshops and still no clear answer, what am I doing wrong?

I have been dealing with this situation for almost six weeks now and honestly I am at the point where I just need someone to point me in the right direction. My Infiniti started showing a warning light about two months ago and I took it to three different workshops hoping to get a clear answer about what is actually wrong. The first place said it was a sensor issue, the second one said it could be related to the exhaust system, and the third one was not even sure and wanted to keep the car for several days just to investigate. Every time I leave a workshop I feel more confused than when I went in and I have already spent money on checks that led nowhere. A friend who has been driving Infiniti cars for years told me I should have gone straight to Infiniti Repair Center Experts Musaffah from the beginning because general workshops often struggle with brand specific diagnostic systems and end up guessing rather than actually knowing. He said Infiniti vehicles need the correct software to read fault codes properly and most regular garages simply do not have it. I checked and it made a lot of sense when I read about how proper Infiniti diagnostics work differently from generic OBD readers that most workshops rely on. Apparently the difference in what information gets picked up is quite significant and that is probably why nobody has given me a consistent answer so far. I feel a bit frustrated that I did not look into this earlier but at least now I understand why I kept getting different opinions. Has anyone else gone through something similar where multiple workshops could not agree on what the problem was and how did you finally get it sorted?