ADE7858, 3P3L,can't measure the voltage of B phase

Hi guys:

My customer use ADE7858 to measure the energy power, and it worked normally by the way 3P4L, and they want to change it to 3P3L, and connect B phase to ground reference(VB-->VN), and it still can't detect the voltage of B phase, and A/C phase is about 80V. any other solution can achieve it?