On my other notebook computer which is running MXLinux, when I saw that the Update icon was showing that updates were available, I did the update but after the update finished, nothing had been updated.
It happened repeatedly over the next few days, so I finally did some investigating and in Synaptic it was showing that there was a problem with the Skype program not finding it's Repository. I deleted the Skype program using Synaptic and then ran the Update icon again and all the other updates that were available, did finally get completed.
I find it strange that the MXLinux update program would prevent all updates from occurring, just because one program (Skype) could not find it's repository. A inexperienced user of MXLinux would probably have no clue, on how to find out why the Updates process was not working.
I think it was doing it because it knew there was a new version of Skype perhaps from a previous repo check. So in effect, there was an update but you couldn't get it. But yeah, that would be totally confusing. I also don't understand why the repo address wasn't forwarded to where the new skype version was. Good ole' Microsoft.