I've had the experience that Kaseya didn't automatically patch (or prompt for a manual patch) for Microsoft Office updates on machines with Office installed but which only had Windows Updates installed. Upon installing Microsoft Update on the computer, and running a local Microsoft Update scan (not through Kaseya), the Office updates appeared (haven't tested to see if Kaseya scanned them subsequently if Kaseya would see them). These were for computers that had been in the field for months or years, with Kaseya running scans on them and patching them regularly.
Kaseya support says that this should not be ocurring, but I have seen this happen many times. I know they use the Windows Update Agent API, but I suspect this leverages the local computer's Microsoft patch catalogue (or leverages the locally running Windows Update Agent for the query), so without Microsoft Updates installed, it doesn't see MS Office (and other MS app) updates.
Have others had this experience as well?
Nope, not seen this happen. Office patches appear in the policies and then get deployed to our systems. I would log a call with Kaeseya if I were you.
I haven't seen this either. Kaseya downloads it's own copy of the patch catalogue and stores this in the agent temp dir, so I'm not sure how you would explain what you are seeing.