VoLTE SIM text message issue Samsung Galaxy S21 Ultra 5G

Daniel_V Posts: 5
edited October 31 in My Mobile
Since receiving the Fizz VoLTE SIM card, my wife is unable to send or receive text messages on her Samsung Galaxy S21 Ultra 5G. When you send a text message with the native Samsung app (Messages version, the phone screen immediately displays an orange exclamation mark and "Couldn't send the message". We have spent hours chatting with Fizz Support, but no success. I also received a Fizz VoLTE SIM card, and it works fine for text messages in my Samsung S10.
In summary, here are some of the tests we have tried:
1. Her SIM card, her phone: no text messages.
2. My SIM card, my phone: text messages work.
3. Her SIM card, my phone: text messages work.
4. My SIM card, her phone: text messages work.
We received a second VoLTE SIM card from Fizz, and it gives the same results.
Other potentially related symptoms:
- In About Phone, the Phone number is "Unknown".
- When she receives an incoming call, the caller information (name/number) only displays "Unknown". (With my SIM card in her phone, the caller info displays properly).
- On power up, SIM Manager shows: "SIM 1 Fizz Unknown Number"
- We have changed Settings/Connections/Mobile Networks/Network Mode from 5G/LTE/3G/2G to 3G/2G. Did not work.

Can someone please help us?
Thank you!


  • Jess_i88b6
    Jess_i88b6 Posts: 11,956 ✭✭
    edited October 30

    Hi @Daniel_V

    Is her phone for the Canadian market or it is an international version?

    If she disables the wifi and make a call, the signal stay in LTE?

    The phone number not showing on can be a delay in the provisioning.

  • Whizz
    Whizz Posts: 17,987 admin

    Hello Daniel_V  , 

    Sorry to hear about the issue.

    From what we understand, this appears to either be a phone issue ( albeit your own Sim card does work in your wife`s phone ) , or a wrong setting set for her specific phone.

    My suggestion would be to just factory reset your wife`s phone , and afterward make sure that the SMSC number is set as : 1-514-424-0053 with more details being found here : https://fizz.ca/en/faq/i-cant-send-or-receive-text-messages

    Reach our customer service on Live chat : https://fizz.ca/en/support if there are still issues.

    Thank you for your understanding.
    Have a good one,

  • Daniel_V
    Daniel_V Posts: 5
    Hi Jess_i88b6,
    SM-G998B/DS (International version). Phone was bought from Walmart Canada about 12 months ago.
    Even with wifi disabled, the phone does not display connectivity mode in upper right. Where can I check to confirm LTE or not?
    We have had the second SIM for over 1 month... Is delay still possible?
    Thank you!
  • Daniel_V
    Daniel_V Posts: 5
    Sorry if this is a double post, but I replied a few hours ago, and it hasn't posted yet...
    Hi Jess_i88b6,
    Her phone is an international version SM-G998B/DS. It was purchased at Walmart Canada approximately 12 months ago.
    I have tried disabling wifi and making a call, but her phone does not display LTE in the status bar. (NB: it does not even display LTE at any time, even if I use the browser). Is there some way I can verify?
    The SIM card was installed over a month ago, and has never displayed the phone number.

    More info discovered this afternoon on the S21:
    About Phone/Status Information/SIM Card Status shows:
    Mobile voice network type: UMTS
    Mobile data network type: HSPA+
    (My S10 shows LTE for both).
    "IMS Registration status": this setting does not even show up on the S21. (My S10 displays "Registered" for this setting)

    Thank you Jess_i88b6 for your help!
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