Please refer to the below steps：

1,Check if the Schedule Record is a 24*7 timing recording
（if it is motion recording policy, it will only trigger a temporary recording when motion is detected ）

2,Check the log records at correspond timestamp at System Maintenance on Main menu,
choose all type and find what happened before and after the interrupt point of record, 
Generally ,a recording will stop when : Device turn off, Abnormal power off, Manual operation, Motion detect, IP channel offline.