Live Caller ID is not working - OnePlus

For Live Caller ID to work, try changing battery optimization settings and set Truecaller as the default Caller ID App on your OnePlus device:

1. In your phone's Settings, go to Battery > Battery Optimization
2. Find Truecaller and choose "Don't Optimize

1) Battery

2) Battery optimization

3) Truecaller

4.) Turn off

Steps to set Truecaller as default Caller ID and Spam App:

Go to native device settings > Default caller ID & spam app > Truecaller.

Note, this is required for blocking calls too.