Wireless Joint

This worked for an EM160R-GL on Visible. Only change:
Instead of
- Set to 4g LTE only Command = AT+QCFG="nwscanmode",3,1
Use
- Set to 4g LTE only Command = AT+QNWPREFCFG="mode_pref",LTE

Technically don't have to do that command if you didn't want too. Could just do this in its place shown below ...

I do not know why it is but AT&T sometimes provisions a hotspot data only sim in certain devices as being 3G (WCDMA or even HSPSA). You will need to contact them to re-provision or (in some cases) send you a new sim. You are not the one at fault it is the automatic system AT&T uses.

I had the same ...

Huh, you gave them the em160s imei? Awesome.

Odd that its not responding to broadband as the APN.

Something sounds like they have issues on the account end. You also may want to call them and confirm the appropriate APN for your SIM and account