TPS65223-Q1: BUCK3 output

Tool/software:

Hi Team,

my customer is using TPS65223-Q1 to power TDA4, they test TPS6522312RAHRQ1 on their board, all outputs work well except BUCK3 is 0,  is 0V the default output of BUCK3? If not, what is the check points to fix this?

Regards,

Stone