I'm still looking for any recorded example that in Measure 6 someone - Vocal/Instrument - sings/plays F natural.
It's always (when transposed to G major) E natural.
I wonder who started that F natural error in M6.
In your provided chart, (at least) the transcriber was able to "match" F natural with Bbmin7.
I've found one chart where the transcriber correctly identified the melody note - E natural but indicated the Bbmin7 chord.
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Another interesting thing.
The oldest recordings of that song I've listened (only two - with Mildred Bailey and Anita Boyer released in 1939) had the bass players playing B instead of G (Root) in Measure 1 (when transposed to G major).
Any later releases of that song had the bass playing the note G (Root.)
And only in Mildred Bailey's version, the bass plays G with Bmin7 chord in Measure 6.
All other versions that I've listened to, had the bass playing root notes of B and Bb
I can imagine that it's an easy mistake to make, to switch the diminished chord to a dominant, and mis-hear that E Natural as an F Natural, just a semitone away and I think many musicians are not very familiar with diminished and augmented chords. Really, in keeping with the chromaticism of the rest of the melody, you could keep the F Natural, make the next note an E Natural and make the D on beat one of the next measure into an Eb and make that Am7 an Am7b5. But I don't hesitate to alter melodies and chords when the it strikes my fancy.