Pandas integration bug: Python3 bytes saves to KDB as symbol

[gowestyang]

When reading from KDB to Python 3 pandas dataframe, as document says:
symbol (KDB) => numpy.bytes_ (python)
string (KDB) => bytes (python)
However, I found symbol is also read as bytes with pandas=True

More importantly, when write a pandas dataframe to KDB, I tested the type conversion:
str (python) => symbol (KDB)
numpy.bytes_(python) => symbol (KDB)
bytes (python) => symbol (KDB)

If in a list, the bytes (python) is correctly converted to string (KDB).
But the bug shows for pandas dataframe.

[dahanaclsa]

I'm also facing the issue. Probable cause is _pandas.py/line 163 casting QSTRING to QSYMBOL