Why is my iPhone 15 Pro Max ringing with no caller or notification?

3 times today my 15 pro max had a call, nothing on the lock screen to enable me to ansert and nothing in recent call list, and no voice mail, in short phone rings for no reason.

phone rings , no way to answer, no caller, no voice mail, no notification on lock screen, any way to fix this, on the latest update, rebooted,

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