Thank you!

That is expected. You can use the Music > Files to Edit > Unsynchronized Tags node to identify these files (it shows all files where database values differ from tags in files). You can select files and use Tools > Advanced Tag Management > Synchronize Tags to save the database values to the files.

When edit tags for unavailable files. it doesn't appear that the actual files are being updated when they become available. This is evident by opening the file in another program or device, and the unedited tag remains.

How do I update this?