Thanks for the report, and the screenshot is useful.
The good news first: your library itself is fine. Adding music to library shows Complete, your counts are all there, and you have music playing. It is the rescan that is stuck, not your collection.
Please try a restart first, because a stalled rescan often clears on its own that way:
Open your Nucleus web administration page and restart Roon Server.
Give it five minutes, then check whether the counter moves past 1.
If it has not, restart it once more. It is worth two or three attempts before we go further.
If it is still sitting at 1 of 8418 after that, please tell us, along with the date and time of your last attempt, and we will pull your logs and look at what the scan is stopping on.
We also noticed the notice about scheduled metadata updates not having run for over 7 days. Have you recently changed something in the network setup.