Up_again is not recorded

At the moment, I have approximately around 1,000 device outages that have not recorded up_again, it is simply a null value. The going_down value is wide spread over about six months. I suppose I could set them all to the same value as going_down, using sql commands but I keep getting more and more of these and I wonder why it is not being recorded to the database when the device is back up again.

Do the affected devices have any scheduled maintenance set? I’ve noticed if maintenance is set after the device goes down, it will not show back up until after the maintenance period has lapsed.

Nope, at least not for that many devices but thanks for the tip.