As a test, I would delete one of the cameras that is exhibiting ths behavior from Alarm.com. Then factory reset the camera and re-add it to Alarm.com.
Cameras are deleted from the ADC website via Video >Settings > Video Device Infro > Select the camera from the drop down then click on the Delete Icon in Video Device Info.
Factory Reset instructions vary from camera to camera complete steps can be found in the manual but most steps can be found here After factory resetting the camera leave it alone for a couple minutes before re-pairing.