I am seeing a long list of “notebooks copy copy copy copy copy” on and on. I delete them in dropbox backup, then one is left in notesplus on I pad. I delete it and it comes back.
This is one of the best app I have used for years. However, since last year there is no support for the app and don’t think developer is interested anymore. I have tried ntoability, noteshelf but inking engine of notes plus still the best of all not taking app I have tried. I suggest look for alternative.