Connectivity with new SIM card iphone 6
Yesterday, while in a T-Mobile store considering a phone upgrade, the T-Mobile representative suggested I upgrade my phone iPhone6 with a new Sim card. Of course I take his advice and he puts in a new card. I live in a slightly rural area and I’m now having “No Service” issues. The T-Mobile coverage map says I should have excellent 4G connectivity, But poor 5G connectivity. Is there a way to make my phone only work via 4G? I am able to make calls with the Wi-Fi option. But, I prefer to have the phone work as it did before the Sim card upgrade(?). Not sure if it matters, but I was a sprint customer converted to T-Mobile. I did a software update but That did not resolve the issue
iPhone 6, iOS 12