Happened to me as well. I figured that it is possible that the cell tower that I'm currently connected to may have issues so I manually switched it in the android settings and it worked.
What I did on mine was:
- Go to Android Settings
- SIM cards & mobile networks
- Press TM/Globe
- Press Mobile networks
- Disable "Choose automatically"
- Wait for network search to finish
- Choose a different "Globe Telecom-PH" mobile network than the current one (there is usually two or more)
- Try to enable RCS in chat
- Repeat by choosing the other one if it didn't work.
If none of the networks work, then towers near you may be having issues.