It could be helpful if you post the drive model numbers but if I recall the NVME drive SK Hynix makes are not compatible with Mac OS. See this post here: #2,761
That happens very occasionally, there is a post here that talks about how some users have solved it. I have not had that issue yet myself. https://www.tonymacx86.com/threads/...ing-up-in-system-preferences-software.308408/strange - my Nuc want's so to stay on 11.5.1, no update to 11.6 found.
Any idea on any hidden setting preventing the update?
Apple stopped providing the previous "combo" updates which allowed a manual process