I had this same exact problem (and regularly have tons of frustrating issues with bullet points) and had to contact support. I ended up having to copy/paste the entire note into a new note, and was able to delete the bullet from there. This post is from a while ago, but maybe this solution will help for next time. For the record, the couple of times I've contacted Evernote support about bullet point issues, they've always been baffled. "Must have been a small corruption" was the ultimate diagnosis, but this happens too often to just be a small corruption in each note. I hope they fix it.