Original topic:

Incorrect working dual sim card smartphone Samsung S21 in USA

(Topic created: 07-09-2022 06:41 PM)
irinamelnykova
Asteroid
Options
Galaxy S21

Hello guys.

I have Samsung S21 dual sim, bought in Ukraine. It was working correctly with both sim cards in UA more than 1 year.

About month ago I came to USA and bought sim card of T-Mobile, here in USA.

Two weeks it was working correctly. Than I needed to instal american application of Bank. In Play Market there was no possibility to instal it, that is why I have change the country from UA to USA and installed it.

After that I have noticed that peole can't make a calls to my american number.

It means the all incoming calls are goes to voice messages. So it is posible to receive only text and voice messages, make outcoming calls. But after restarting the phone only 1 or 2 incoming calls are receivening and all the rest are goes to voice messages.

What have i did to resolve the problem:

1. I have check if the sim card is working correctly at other smaptphones - yes

2. I have tried to set up the country in Play Market back again to UA - doesn't work, only once a year could be changed

3. I have delete applicaton I have set up in USA (bankofamerica) - doesn't help

4. I have change sim card at T-Mobile shop to new one - doesn't help

5. I have turned off UA sim card - doesn't help

Will you please advice me what to do ...

P.S. I have been working in Brand Shop Samsung in Ukraine 2 years, so hopefully I could manage to resolve the problem ...

6 Replies
Bs2209
Sun
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Galaxy S21
Try a network settings reset maybe 🤔
DanG92263
Neutron Star
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Galaxy S21
Okay, here's what I think is happening.

Your SIM card and region has been updated to the US, but your original bios is still UA or Ukrainian. Need to have your carrier update the bios to US to work properly on their network. Doing this could delete the data and photos on the phone, so be sure to back up your stuff.

Since your region and SIM card are set to US performing a factory reset might reset the phone to US settings, but I'm not sure of that. It might just factory reset to the original bios and software or, worst case, brick the phone.
irinamelnykova
Asteroid
Options
Galaxy S21

Thanks for your unswers, guys.

I really appriciate it.

I just remembered I had Android updation about two weeks ago, I alreay have beed in USA.

Could it be some bugs in last version?

 

Best regards, Iryna

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bill-e
Samsung Care Ambassador
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Galaxy S21
Check your CSC code. You are likely still on the Ukraine firmware, Here's the way to determine that. https://ihax.io/samsung-csc-codes/
** If my response helps, please click on Like (Heart). If I resolved your issue also please click on Accept as a Solution so that others can benefit.

Bill
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Galaxy S21 Ultra 512g(VZW), Galaxy Book (original, VZW), Tab S8 Ultra, Tab S4, Galaxy Watch3(VZW), M8 Smart Monitor
irinamelnykova
Asteroid
Options
Galaxy S21

Hi Bill.

Thank you. 

Yes, I still on the Ukraine firmware. CSC code - SEKScreenshot_20220711-091128_Settings.jpg

  

Best regards, Iryna.

0 Likes
Options
Galaxy S21
To fix this problem, Samsung should at least move all US carriers on the U1 variant to a single XAR firmware, and place it in the OXM (NOT the OYM) group with SEK, as shown, for example, SAOMC_SM-X900_OXM_XAR_12_0002. This could help break barriers in terms of SIM card and display language support.Screenshot_20220720-235730_Settings.png
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