Thanks for reaching out. Make sure you plug in and turn on the Sylvania SMART+ light in the same room as your speaker or display. Try these steps in unlinking your lights from the Google Home app:
Notes: You can't unlink individual Sylvania SMART+ lights. If you remove one light it causes the removal of all Sylvania SMART+ lights.
Just checking in to make sure that you saw my response. I'll be locking this thread if we won't hear back from you again in 24 hrs. Should that happen, feel free to create a new one if you have more questions or have other concerns in the future.