- Edited
For what it's worth, things I did to get it to work;
- used default "Owner" profile
- installed google play services, permissions Contacts, Network, Phone, SMS
- installed carrier services, allow Unrestricted running in background
- installed Messages, permissions Contacts, Network, Phone, SMS, storage spaces setup, set SMS app to Messages
- chenxiaolong this step here
- turned off any VPN, WiFi (to use mobile data)
- open Messages, turn on RCS
- wait around 5 minutes
- working!