hi my friend,
please check the ftdi board to hc06 pin connection according to picture which i uploaded ,
generally poor or wrong pin connections (RTS-DSR-RI-DTR) gnd and VCC 3.3v are cause that problem,
on the other hand please re-check HC06 module has BC417BGQ marking
i also tryed on ESP32 and works good, but didn't tryed on HC06 modules yet,
Could you please share to me the HC06 dump for SM2pro , here but on external link
because i dont have enough credits to download on forum yet..
sorry for english