Calling 110 on China Telecom fails and causes the phone to lose reception until it is rebooted

[fffelix-jan]

Describe the bug
Calling 110 (the police emergency number in China) on China Telecom fails and causes the phone to lose reception until it is rebooted. (This might also apply to the 119 fire and 120 ambulance numbers, but luckily, I've never had to call them so far.) This bug may be dangerous in a life-threatening condition.

To Reproduce
Steps to reproduce the behavior:

1. Be in China, use a China Telecom SIM card and enable VoLTE using Pixel IMS.
2. Open the Phone app.
3. Call 110.
4. The phone fails to call 110 and displays "No Service" until the phone is rebooted.

Expected behavior
The police are called. (This issue can be worked around by calling <areaCode> 110, which I can confirm works in Hangzhou by dialing 0571 110.)

Smartphone (please complete the following information):

• Device: Pixel 6
• OS: GrapheneOS Android 15 (latest version)
• LTE-only mode (2G and 3G are disabled)

Additional context
I have a feeling it's due to the special way the phone handles emergency numbers.

[fffelix-jan]

Reminder: 110 is an EMERGENCY NUMBER! Please do not call them if there is no emergency!