Mexico-T-Mobile Mobile Data issue on S22 Ultra e-Sim

My guess is going to be that potentially the carrier you are roaming on to doesn’t support or fully support eSIM.  

Going to Mexico City again and will update the USA T-Mobile e-SIM Experience again.

eSIM-Service - Pre-Paid
Plan - T-Mobile prepagado de 10 GB 
(Todas las llamadas, textos y datos nacionales que puedas usar con hasta 10GB de 4G LTE por solo $40 al mes, para que tengas un acceso de alta velocidad cuando más lo necesitas. Comes with Music Unlimited so you can Jam all day without using your data on included services.)
Servicios - México y Canada Unlimited (USD $5 Add-On activation with Customer Service Help)
(Obtén llamadas, textos y datos LTE ilimitados en tu smartphone en los EE. UU. y datos ilimitados mientras viajas en México y Canadá, con hasta 5 GB a velocidades 4G LTE. Como bonificación, obtén mensajes de texto ilimitados en México y Canadá. Best of all, the whole package is just $5 more a month)

https://www.t-mobile.com/coverage/coverage-map
When you complain to T-Mobile, be sure to mention that T-Mobile’s roaming maps show service in the City or Area and that they should either fix the roaming or the map

https://community.t-mobile.com/network-coverage-5/unable-to-access-internet-data-in-mexico-appeared-pdp-authentication-failure-38500

More Troubleshoot for this Kind of Issue

https://community.t-mobile.com/network-coverage-5/international-roaming-india-has-issues-38006/index2.html

Nebulo (because it was free with no ads or purchases)
https://play.google.com/store/apps/details?id=com.frostnerd.smokescreen
The same developer has an older app that I found worked a bit more reliably than nebulo
https://play.google.com/store/apps/details?id=com.frostnerd.dnschanger

More troubleshooting On the phone goto:

Step1: Cellular data > Network selection : change from automatic to manual selection (or disable auto)

Step2: Wait for list of roaming operator's to populate

Step3: select a national operator in your area

You may need to restart phone after step3 And recheck step3 to make sure correct operator is actually selected. Once set it should remain until next restart or airplane mode.

Amazing that this issue still continues. It is definitely not a problem with the local carrier and esims. I had the same problem in Canada and had to resort to using Airalo eSIM which worked fine for data. 
I wonder how much revenue T-Mobile is earning from customers that spend $5 and get nothing. It's such a long process to go through the troubleshooting that eventually you just give up. 
Everything points to this being a coding issue and no one thinks it’s important enough to spend some time and resources to fix it. 

I have never had any issues roaming in Canada.  I don't use an eSIM though but Bell/Telus, T-Mobile's roaming partner in Canada does support eSIM.  Whether or not T-Mobile's eSIM implementation is compatible with the mess Bell/Telus use, I have no idea.

Gracias @SSP. I think you just confirmed that it's a T-Mobile eSIM issue. The eSIM is seeing the network but only connecting with the part of the network for calls and SMS. It is unable to connect to the data side of the network. That points to a problem in the code of the eSIM. If it was a problem with the Mexican network, then your physical SIM would not have connected to the data. Hopefully, as eSIMs become the norm, T-Mobile will be forced to address this issue. Apparently, they are not yet getting enough complaints as yet.

Same here, I have no connection in Mexico, but my wife does have internet. Im on a esim and she is on a physical sim. The strange thing is the Im able to connect just while using a VPN but not without it. Does anyone have any idea why?

Each carrier's eSIM implementation can differ, just like how VoLTE, VoWiFi, and other carrier specific features can differ.  It is going to take a long time before carrier's start to worry about their roaming partner's eSIM's.

Yes, I sent this thread to T Mobile Customer Service so that they can forward this to Technical Engineering Team. Unlocked Mobile, Simple Prepaid Plan(Not a Magenta One)
The Final - Root Cause is in eSIM Code which is not compatible with Roaming Partner(TELCEL). where as Physicals SIM works Perfectly with USD$5 Add On.

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¡Gracias por contactarnos! I appreciate you for taking time to work with us regarding this issue while traveling. I know it's important to stay connected. I see we advised you it would take 72 hours for there to be an update. At this point its only been 2 days so we are not at the 72 hour mark and there is no update at this time I would recommend continuing to connect to wifi whenever possible while our team continues to work on those tickets. I appreciate all of your patience while we work to address this. ^JonPorter
Sure Jon,  Will wait for another Day More

Awesome! I do want to make sure we set proper expectations for you. When traveling internationally we aren't able to guarantee a specific level of service since you are using a international network. So coverage and data capabilities are going to vary. ^JonPorter

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Thank you for getting that completed. Great news! I do show that you are connected to the network based on the following: 
Roaming: Mexico | Roaming internacional
Carrier: Telcel Radiomovil Dipsa,
I see you stated it showed LTE on the device. Have you gone into the actual settings of your device to disable the 5G option completely for the time being? ^LitaIngram
Now I'm at LTE/3G/2G(Auto Connect)
Let me run the Speed Test
Same issue Speed test are not able to find the Provider and Server and showing Error

Thank you for updating those settings. I would like to try one more option. Can you try the link here: http://theoldpurple.com 
Based on your current location, this may help with testing things out. This sites page leaves a very small footprint and it works on even the slowest connections. 
Can I have you try that out? ^LitaIngram

Yes, it open t mobile web page
but browser still shows no Internet connection

Thank you for confirming that. I truly appreciate you allowing me to research those details for you. After further review, although it shows you as roaming on the partner network, there aren't any additional steps to take to ensure we can guarantee those connections based on the area. No additional ticketing would need to be submitted because the expected coverage per that area is to be low. I know this wasn't the resolution we wanted to give, and I truly want you to have those connections while traveling. I recommend being connected to Wi-Fi as much as possible throughout your remaining travels within that area.

Taking our time to review all of our resources to help find any needed details or resolution is what we are all about, so I appreciate you allowing me time to research that further. Are there any other details I can help with at this time? ^LitaIngram
14 de feb. de 2023 3:38 p.m.
 

Daily I'm spending 1 Hour Discussion to T-Mobile Customer Service. Repeating whole History again but everything end's to Zero. Since last 10 Days I'm on without data in Mexico city. Mexico.
the 72 Hour Resolution are just mockery.