Items go offline for awhile and it won't tell you or log it.

Items online and it will say it is offline (more rare).

Some issue and you get a string of notifications over a few days that a device is going offline. But you never get a notification when it comes back online or a log showing when it came back online. Making it impossible to draw any conclusions.

Missing info from the Ovrc Pro scans. Items you know are online but does not show at all.

And all logs only go back 1 month on a device. But that isn't a bug, it is a feature :)