I have not found the auto sync method in Premiere to work very well, I get the same 'non sync' results as you. A number of people use Pluraleyes but there several threads on this forum with people have trouble later in the edit after importing the Pluraeyes sequence. The adaptive track was, I think, Adobe misguided way to mix stereo and mono clips on one track. I think you are better off using mono track for mono clips and stereo for stereo. I sync all my rushes by hand using the waveform from the camera guide track and the master sound.
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