Cannot connect to internet in Safari

I have called AT&T and Apple and no one seems to have a solution to this. This happened on my 6 plus and is now happening on my X. When I open safari and type something in the address bar, whether it be something to search, or a web address, nothing happens. It just sits there. Eventually, I will receive a message stating "safari cannot open the page because your iPhone is not connected to the internet on LTE" If I am on Wifi, everything works fine. All of my apps work great, including email, messages, and everything else internet related. This is only Safari and Chrome. I have 4 bars of LTE service. I have reset my network settings, rebooted my phone, taken it back down to box, gotten a new SIM card, and AT&T has rest my phone no less than 5 times. All of this items are temporary fixes, as in fixed for maybe 5 min and then doesn't work again. Can someone please tell me what this is and how to fix it?? I am so ready to switch to an Android. I thought buying the X would solve the problem, but it has not. It is very troublesome when new cars do not come with navigation anymore because they all come equipped with CarPlay now. I can't even get my phone to pull up the address in safari that I am going to or a business's hours when I need them. PLEASE HELP!!!