On May 3, 1919, 6 months after the revolution, Hitler said he was in favor of majoritarian democracy at a meeting of members of the 2nd Infantry Regi… - Thomas Weber

The question is not whether Hitler supported the left during the revolution, which he clearly did, but what kind of left-wing ideas and groups he supported or at least accepted. As Hitler served all left-wing regimes during all phases of the revolution until the end, he obviously accepted all of them or at least acquiesced to them for reasons of expediency.

Auer, himself, also claimed that Hitler had held sympathies for the SPD during the winter and spring of 1919. In a 1923 article Auer wrote for the Münchener Post , he stated that Hitler ‘due to his beliefs was regarded as a Majority Socialist [Mehrheitssozialist] in the circles of the Propaganda Department and claimed to be one, like so many others; but he was never politically active or a member of a trade union.

[O]n surviving film footage of Eisner’s funeral we see Hitler with a few men from his unit walking behind Eisner’s coffin in the funeral procession of the Bavarian leader. We clearly see Hitler wearing two armbands: one black band to mourn the death of Eisner and the other a red armband in the colour of the Socialists revolution. Similarly, Hitler appears on one of Heinrich Hoffman’s photographs of the funeral process for Eisner.