I started out on Tracphone,then switched to At&t Gophone to get better coverage.(I had horrid reception with tracphone phones when I went camping/floating) At&t (Gophone? is what they call it when you but their burner phones),prepaid phone lets me use any GSM unlocked,or At&T branded phone that I could put a sim card into.
I believe tracfone works off of different cell carriers' towers, depending on where you live. For instance where I live I believe mine primarily uses Verizon towers, but if traveling it may go through other carriers' cell towers, such as AT&T. I'm not sure how long ago you switched, but I know in the last ten years I haven't had reception problems out of town, where previously I couldn't get a signal.