Timestamp is {null}


On some computers after running Get-CimInstance -ClassName “Antivirusproduct” -Namespace “root/SecurityCenter2” I got an error that timestamp is null. Only thing which I have found out is that the timestamp is the time when a product was installed on the pc. I can’t find info what are possible reasons for that timestamp to be null and if it is null what are the best ways how to handle those situations. Also I am not able to see what exactly returns this command, but seems that other information is not empty. Does anyone know why timestamp can be null and if it is, what should be done about it?

Thank you!