change the 6th index value related to maximum call volume if you find it difficult . see the video on youtube. i just posted there https://youtu.be/ZW0Ia_wzJcA
if you still have problem please let me know.
Like you increase the value of NB do the same to WB .You will find the setting of WB where you increase the value of NB. When you select NB you will see WB do the same thing 144 to 160 on 6th index