No data connection in any mall - Go Unlimited Plan

[DAVMOO4]

I switched from ATT to Verizon Go Unlimited Plan 10 days ago. Since switching, any time I step in to a mall [2 malls in my town] I am unable to connect to the internet despite seeing 2-4 bars and the word LTE being displayed in the phone. I went to Apple and they checked the phone to make sure it is not a device problem. I understand that Verizon can throttle speeds down during congestion but there is no data transfer at all???

Any one else have this problem. I did not realize that Verizon is so terrible. Will I be able to switch back to ATT?

Thanks.