I'm fairly certain I was taught about conflicting evidence and, even more importantly, differing interpretation of events in school, for example we discussed the role of the US and the Soviet Union in the cold war quite extensively and controversially.
You really went to a different school than I did then. In the 90's, I was taught history purely as "This is what happened" with zero mention of debate, evidence or conflicting conclusions. I was explicitly taught that the civil war was fought over states rights alone. I was taught that the US was sparsely populated before Europeans arrived with glorious civilization. I was taught that democracy was triumphant and the best system of government that could ever be, and better in every way than the failure of Communism. I was taught that we alone saved the world from fascism in WW2 with barely a mention of the eastern front. I was graded on my ability to recite these facts.
Sure, I am aware that actual high quality historical scholarship must exist, but I honestly wouldn't know where to find it without waking into a university and asking someone close to the field for research help. Nearly every book of history on the shelf of my local library is in the vein of Guns, Germs, and Steel. I enjoy listening to some history podcasts, but have mainly experienced them as good storytelling and nothing about how the sausage is made.
Of course, if you went to school in the northern United States, you learned the Civil War was about slavery disguised as state's rights.
But yeah, 5th through 10th grade history, there was no nuance, just "this is what happened, this is History, this is the textbook, this will be on the test, the end."
A handful of excellent grade 9-12 teachers would have you do primary source research[1], and there you might get some conflicting sources, but you just discarded the sources that didn't work with your thesis topic. (See how this works? Thesis first, then sources...)
It was only once I was in college that we really got into some of the nuance of multiple sources and working from the ground up instead of the top down.
[1] Specific examples that I recall: did an astronaut biography in 5th grade, I interviewed my grandparents on 1930s Depression-era life in 9th grade; I did a primary sources (newspaper on microfilm) paper in my college sophomore year (14th grade) on the The Rainhill Locomotive Trials of 1829 in London, England.
I'm fairly certain I was taught about conflicting evidence and, even more importantly, differing interpretation of events in school, for example we discussed the role of the US and the Soviet Union in the cold war quite extensively and controversially.