The network is set to 3g, however there is no way to change that. And my friends that also have motorolas and AT&T get 4g LTE and it works good for them.
Try using AT&T's APN settings (see link below) to create a new APN entry on your phone and see if that makes any difference. https://forums.androidcentral.com/e...rt/article/wireless/KM1062162/&token=YNV9BdmJ
Pay attention to the spelling and punctuation and duplicate the settings exactly, and don't add space characters. (i.e. no space after a comma). And when you select the new APN entry you just created, be sure to restart your phone so it gets loaded during the boot up process. (switching APN isn't done by just picking a different one, you need to reboot.) Then see if there's a 4G/LTE option visible.
If this doesn't work out, you should contact AT&T and see if they will send you a new SIM card or have some insight to your problem. Your Moto G7 Play is a capable phone that includes support to 4G/LTE..