[ronie]

if you stop music playback, the lyrics window should reappear when you start music playback again and go to the fullscreen visualisation window.
or, during music playback, you can exit and re-enter the fullscreen visualisation window... that should work as well.

and if even a restart of kodi doesn't help, then something else must be wrong.
- check if the addon is still enabled
- check if 'display lyrics automatically' option is still enabled in the cu lrc addon settings