Hi,
My mirror is the same than in this post:
https://support.plesk.com/hc/en-us/articles/115004292734-Microupdates-are-not-up-to-date-the-process-of-updating-finishes-successfully-but-MU-installed-is-not-the-latest
They say to edit a file (Specify default Plesk repo, using any text editor...