4g LTE only works in home city
Hi, I had to switch carriers for work and brought my Galaxy S9 from Verizon Wireless to AT&T. When I first switched, I was unable to use 4g LTE internet and was only able to use H+ access even after configuring my Access Point Name information. We figured out it was because the AT&T network could not identify what kind of device I had. The in store technician changed the "Device Type" associated with my number to reflect a galaxy s9 and it started working. However, now whenever I leave my home city of the Dallas-Fort Worth area, I do not get 4g LTE internet. To rephrase, I get 4g LTE in Dallas-Fort Worth but as soon as I leave (to places like Seattle, Chicago, New York City), I get H+ as my best data service.
My network mode is Global and my APN settings match what is reflected here: https://www.att.com/esupport/article.html#!/wireless/KM1218306
I went to an AT&T store in New Jersey today and they made sure all the correct information about my device was reflected in AT&Ts system like IMEI, ICCID, phone serial number, etc. and it all checked out. They had no idea what the issue was.
Does anyone have any idea how to make a Verizon Galaxy S9 work on AT&T's network properly?