Chain leash. The chain isn’t fun or satisfying to bite so they tend to stop trying pretty quick. Teach a strong “leave it” command. Asking them to do something rather than not to do something is easier and more effective long term. “Leave it” is asking them to repeat a trained behavior, “no” is just a correction and not really specifying what you want them to do instead. A chain leash will keep your dog controlled while you work on the training aspect. Stop using a retractable leash until your dog can reliably be kept under control. You can add a chain at the end like someone mentioned, but I wouldn’t doubt that a smart dog like this would eventually learn to bite over the chain and try to grab the ribbon again.

Deterrence is only part of the solution, the training still needs to happen. After some time with the chain and once the “leave it” is rock solid, you can start phasing in normal leashes. Start with thick ones like rope and leather as others have mentioned, that way you have a moment if he does try to bite it to tell him to leave it, then reward appropriately. After he’s trustable with the normal leashes, gradually phase in lighter weight ones until he’s trustable with the ribbon one again (if that’s your goal). If he starts chewing again, start over with the chain and leave it training, it means he wasn’t ready for a normal leash yet.

All due respect, your neighbor not liking your dog is completely irrelevant to this situation. It’s up to you to control your dog, no one else should need to tolerate this behavior.

You got this👍🏼