Don’t see lyrics for any song in the library. The button is grayed out. What can be done?

From the Related Article above.

If the Lyrics button is grayed out

If nothing happens when you tap Lyrics, then either you’re playing a song that's not from the Apple Music catalog, or lyrics aren’t available for that song.

Some things you can try. Do you have access to another WiFi network where you can try? That has worked for several people.

Try a restart.

Restart your iPhone   *

Restart your iPad.   *

Try a forced restart. See the section towards the end of the article.

Reset Device. -

If necessary

Hard reset.     -

Do a backup and try a factory reset. Then restore from the backup.

Restore to Factory setting.      *

Restore - If you see an error when you update or restore your iPhone, iPad, or iPod.   *

Backup - Restore your device from an iCloud or iTunes backup.     *