Some of the Biab dataset's Harte bass notation is wrong

[Bmoist]

Here's a sample from the 21th piece's chord info in the Biab dataset. The piece is Chopin's Waltz in C# minor, Op.64 No.2.
C#:min/b1
D#:(3,5,b7)/bb1
G#:(3,5,b7)/bb6
G#:(3,5,b7)/bb9
C#:min/b1

By Harte chord notation's definition, the number after the slash represents the bass note. In the actual score, the corresponding bass notes are: C#, D#, G#, C#. The b1, bb1, bb6, bb9 thus does not make any sense.

This problem may exist in the other 491 pieces (where a double flat bass can be found)