Your phone may automatically latch onto a weak partner network, making the connection unstable. Selecting a network manually usually fixes it.
On iPhone
- Settings → Cellular → select the Coral eSIM line
- Open "Network Selection"
- Turn off "Automatic" to see the list of available networks
- Pick a different operator (if it doesn't connect, try the others in turn)
On Android
- Settings → Network & internet → SIMs → select Coral eSIM
- Turn off "Automatically select network"
- Choose an operator from the list
Connecting can take a minute or two. If it doesn't work, switch back to "Automatic" and toggle Airplane Mode.
Related: eSIM isn't working / slow data speed