I started getting a phantom notification at odd times on my iPhone. Went through usual stuff in settings and notifications. No joy. Looked on forums and although others were suffering too there was no solution that worked for me. One post said try putting all banners on and see if a banner came up when that irritating phantom notification bleeped. Joy it did. It was a web cam that was notifying me of a movement. This worked even though all notifications was switched off. The camera is not mine and it seems my family member ( whose camera it is) had inadvertently switched the motion notification on. All is well now.
Hope this helps one or all of thou phantom notification sufferers
Hope this helps one or all of thou phantom notification sufferers