I don't want to hijack DisamDev's post, but I have the same issue. In my case (it might not be an issue for Disam) I do want to allow registration signups through Kinde, but only when they go through the registration flow. If I disable that setting it does prevent users from signing up, which may solve Disam's problem. However, it also prevents registrations through /api/registration. (It gives a 404)