Please follow the below-mentioned troubleshooting steps:
1) Logout from the app and uninstall it first from your device.
2) Later, restart your device once and download the latest CallHippo app from the Apple store.
3) Once the app is installed, log in with your credentials and set to “allow all the permissions.”
Settings-->Applications-->CallHippo-->Permissions--> all permission should be allowed (including storage and phone)
4) Make a test call for incoming and outgoing. The calls should start working.
In case the above steps do not help, we would also suggest to please switch the network and try i.e., if you are using wifi then switch to 4G mobile data or vice-versa.
Re-login into your iOS App and you should be good to go.
Hope this helps!
For further queries, please contact us at [email protected].