TPS3820: TPS3820-The watchdog failed to recognize the feeding signal, causing the system to keep resetting and preventing it from operating normally.

Part Number: TPS3820

The test revealed that the abnormal watchdog failed to recognize the dog-feeding signal, causing the system to keep resetting and thus unable to operate. The level and width of the dog-feeding signal met the requirements specified in the manual.The defect rate is 47.5%. Could you please help me figure out where the problem lies?