Can’t send text messages

[Shayne8]

My dad is able to receive text messages (I believe because they are RCS) but isn’t able to send anything.  I’m a few hours away so not able to look at the phone right now. Any tips? It looks like he’s got the eSIM as the primary and the SIM 1 from old carrier is turned off 

[softech]

@ 

make sure the old carrier sim is really turned off, then try Reset network settings after a device reboot

Then check again, also confirm both incoming and outgoing calls work

If text still an issue and if he has an Android, try uninstall Google Message (or Uninstall Update if that is the only option) and then reinstall after a device reboot.  That would force a RCS re-registration