It appears that the asset report exports only information for endpoints currently online/active. Surely, this is a bug and should export all--in an enterprise environment, machines are offline in the normal course of business. If this is by design, Malwarebytes should add the option to export information for ALL endpoints. This export is not reliable for decision-making otherwise.
Enterprise use of Malwarebytes may incur several custom exceptions for false positives or accepted risks. Consider adding a notes textbox with each exception created so we can document why it's needed or other useful information for the administrators.