I still have this issue as well using Arch Linux Phosh. The device was working perfectly and then suddenly no text could be sent. An orange exclamation mark appears periodically and when this is present I can send text - but I can always receive text. Also when this exclamation mark appears I have no access to my Evolution email through sim card or Falkon web browser. When I reboot the device and get a normal 2 to 3 bars signal strength I can still receive text but cant send text. Phone calls work fine either way. Internet access also returns properly. I suspect strongly this is due to a Gnome-Calls update back in March-April. It's not a bad situation for me as it is more important to receive text than send and I always want Evolution email and Falkon browser access.
---------------------------------------------------------------------------------------------------------------------------------------------------------
Edit: May 18,2022
I have noted that by enabling or disabling mobile data will have different effects for different functions.
Disabling mobile data allows me to send text and the exclamation mark appears in banner over sim card strength (but I can always receive text regardless)
Enabling mobile data terminates my ability to send text and exclamation mark disappears (but can always receive).
With mobile data enable I can also access internet data through sim card.
It seems to defy logic but thought I would share this observation with the community.
----------------------------------------------------------------------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------------------------------------------------------------------
Edit: May 18,2022
I have noted that by enabling or disabling mobile data will have different effects for different functions.
Disabling mobile data allows me to send text and the exclamation mark appears in banner over sim card strength (but I can always receive text regardless)
Enabling mobile data terminates my ability to send text and exclamation mark disappears (but can always receive).
With mobile data enable I can also access internet data through sim card.
It seems to defy logic but thought I would share this observation with the community.
----------------------------------------------------------------------------------------------------------------------------------------------------------