Hey @Peter46
I was unable to reproduce this issue of MainWP Dashboard incorrectly reporting that Core needs to be updated even when on latest version.
If the issue reoccurs for you, please open a private Help Desk ticket and we will gladly look into this: https://mainwp.com/my-account/get-support/
To make it easier for everyone to follow the discussion around that issue of Site IDs being shown after Core updates, let’s continue troubleshooting in the thread @josklever opened.
Feel free to also provide answers to questions I asked Jos’ in my message here: Update status WP core shows site id - #2 by bojan