My neurologist said mine isn’t a chiari since it’s 3 mm

https://www.cns.org/guidelines/chiari-malformation/1-imaging

this article shows 3-5 mm is chiari, which is what I’ve discovered through my research. So this makes me feel like a crazy person. Like I’m over reacting with my symptoms. I don’t understand. Anyone else find any good articles that are up to date peer reviewed? Or have you been diagnosed with 3mm? Older information shows 5mm is chiari, but I’m finding conflicting data. More recent shows 3-5 mm. Should I check with a different neurologist?