We purchased the LTE Falcon hotspot for the specific purpose of using it in Baja Mexico in major cities. The LTE hotspot worked one time in Baja and then stopped working. It appears T-Mobile is not working with the Baja, MX carriers because only their service is cutoff. My friend's AT&T and Verizon data plans both worked perfectly. I changed the SIM card went back over the 4th of July weekend and had no internet while my friends enjoyed theirs. In addition my wife's sister has a T-Mobile phone and indicated it stopped working in Baja Mexico a month ago. We sat down with both devices in Baja and called a T-Mobile support representative who was unable to figure out why we had no internet. You can connect but can't communicate on LTE/4G/3G. My guess is T-Mobile is struggling to pay the bill for MX access because there is no other reasonable explanation.
Below is the list of cities where my friend's Verizon phone and other friend's AT&T phones worked 100% of the time for data but the T-Mobile Falcon LTE hotspot did not.
Tijuana, MX population 1.3 million,
Rosarito Beach, MX population 65,278
Ensenada, MX population 519,813
Have you tried manually selecting different carriers? Some people have complained about the data service on one of the carriers down there.