Recovering a Locked Note

Do you still have the previous device? Or another device (like an iPad) where you can still access the note? If so, open the note, Copy and paste it in a new note so it shows up on the new device also. Then set a new password for it on the new device. Make sure it works as expected. Not an official fix but it’s one I have had to use in the past

The only way to 'recover' the note is to remember the password you used to encrypt it.