I have iPhone 14 Pro Max and never have any connectivity issues. But I do live in an urban area, which a lot cell towers around me, wherever I go. Do you have connectivity issues everywhere you go or just in certain locations? Have you tried to set the Cellular option to LTE as opposed to 5G Auto, incase you live in an area with poor 5G service? Do you have Wi-Fi Calling turned on?
You might want to have your iPhone checked by Apple. You can schedule an appointment at your Apple Store Genius Bar. Here's a link to help you --> Genius Bar Reservation and Apple Support Options - Apple