Lowering the monthly cost of mobile phone: T-Mobile vs. Mint Mobile (Part 5)

Here's a quick update from my experiences after part4:

Domestic (USA):

Voice, Text, Data work very well on the areas I regularly go. Sometimes I've the feeling that there is a slightly worst quality on the phone call or data connection, but it's hard to notice and the lower cost of Mint Mobile makes up for the difference.

Customer support service by email answers in 48 to 72 hours, and after that, they followed up every day until case closure. The chatbot from Mint Mobile web site is useless and a waste of time. Nobody ever answered me via the chatbot. I had to send email to support.

International:

Voice and Text roaming worked fine.

Data roaming did NOT work.
WIFI Voice Calling did NOT work.

The T-mobile service did not have any problem with Data and WIFI voice roaming. However, Mint Mobile does not connect at all - as they advertise -.

As far as I can see, Mint Mobile is unreliable when traveling overseas.