Do you have a policy that is supposed to include “Every Database” as part of its condition, but for some reason it never includes the system databases? The “Every” condition is a built-in condition that cannot be changed and does not include system databases.
If you want to include the system databases in your policy you need to create a new condition that includes both user and system databases. Once you have created the condition you will want to go back to any policies that need this change and alter the target condition to point to your newly created condition. Here is what that condition might look like:
Normally you can click the hyperlink in your “Against Targets” condition to open and edit the condition. If you click the hyperlink and the condition does not open, then you know it is a default system condition. Go ahead and click on the “Every” database condition and you will see that a whole lot of nothing happens.