iPhone Pro won't load web pages

I am unable to load web pages on my iphone 11 PRO.

What's happening? When using cellular network, and seeing FULL bars on AT&T coverage, I can't load any pages. Whether it's ESPN.com or CNN.com, etc. It looks like it's going to load but freezes up for minutes.

I went to Apple support, and they rebooted my phone, reset it to original settings. It didn't work. They gave me a new phone. Now, my new phone has the same exact issues. Performance is terrible and it only works on Wifi. HELP !!