It's also possible that this is related to previous UEFI updates; there was an issue where those would be pushed via the same update paths are OS and app update

It's also possible that this is related to previous UEFI updates; there was an issue where those would be pushed via the same update paths are OS and app updates, but sometimes they would time out and not get installed; and then never get tried again. Not sure on what models this happens, but if that is the case we could be dealing with an issue related to different starting versions of the firmware during the update. Interesting to say the least.