Hello Coogy and welcome to Apple Support Communities.
I see you have a question about using the lyrics generated by the Apple Music service versus ones you added by hand using the processes outlined here:
View lyrics in Apple Music - Apple Support
"If you don’t have Apple Music, you can add custom lyrics for a song on your computer, but those lyrics won’t sync to other devices. In the Music app on Mac or iTunes for Windows on a PC, click next to a song’s name and choose Get Info. On the Lyrics tab, select Custom Lyrics, then enter lyrics and click OK."
As custom lyrics are part of the metadata file for a song on any given device, they would also need to be removed manually in order to use the Apple Music-generated lyrics instead.
Cheers.