@Or Tsemah
Having spent some time digging around in our on-prem environment, it looks as if these are objects the have been tombstoned in our AD, probably with the devices in question having been rebuilt multiple times, so this was a false alarm, sorry for wasting your time :facepalm:.

Would it be at all possible to surface the DeviceObjectId property of devices in the downloadable versions of the LAPS reports? This would really help us in reconciling the data, as it is a common identifier between on-prem AD, Azure AD and MDI/MCAS.

Once again, my apologies for the false alarm.