BQ500211A

The TI EVM passed at this freq and it is normal for customer applications to pass also.

The Out of Specification freq of 40 MHZ sounds close to the internal osc freq of the bq500xxx.

Take a look at the filter capacitors and RTN for V33D Pin 33 and V33A Pin 34.

Additional high freq filtering on the pins may help. Adding filter capacitor with better high freq performance such as 0.01uF or 1000pF.

Also good connection between ground Pin 32 and Pin 36 and filter capacitors have been problems in the past.

Other thing to look at it the gate drive, add 10 to 20 ohm resistor in series with the gate.  But a problem here is often seen at freq higher than 40MHz.