I've got an iPhone 13 and I am in downtown DC. In my office (which is a 100-year-old big brick building) I've got 2-3 bars of signal showing LTE. Yet on a regular basis when I go to open a webpage on my phone it will take over a well beyond 60 seconds to load, if it loads at all. Sometimes if I walk to the window its better, but the signal showing on the phone doesn't change when I do this. When I walk outside of the building, I still have 3 bars, but I immediately jump to 5G and can access the internet. Given what I am experiencing it seems clear that the signal in the building is somehow significantly degraded by the massive 100-year-old concrete bricks that makeup the exterior of the building. Yet if that was the case, I would assume I should see that I only have 1 bar or signal, or I would expect to not see the LTE sign.
I've tried resetting my network settings and that got me nowhere. Given that I'm in a federal building there is no wi-fi that I can connect to. Any suggestions on what might be going on, if there is no signal that would be one thing but I'm getting indications that I should be able to access the internet.