Hitler wasn’t a Fascist, Mussolini was. Hitler was a National Socialist, which is a distinct ideology from Fascism. Both are types of socialism, as is Communism. Another name for Communism was International Socialism, which lasted until Stalin realized that worldwide revolution was never going to happen and proclaimed that the USSR would practice “Socialism in One Country”.
This is basic history, though it’s not taught by socialist and socialist-leaning history professors/teachers for obvious reasons (they want to distance themselves and their ideology from the one socialist genocide they can’t deny: the Holocaust). In the thread you’re whining about,
@MarvinTheParanoidAndroid shared sources showing this only to be dismissed out of hand with the excuse being that since his sources were videos and PDFs, they didn’t count.
On the political spectrum where Communism is the farthest left you can go and Anarcho-Capitalism the farthest right you can go, where would National Socialism and Fascism be placed? The answer is right next to Communism, on the far left.