Resolved
Incoming and outgoing calls are working as expected in the latest update.
Monitoring
A fix has been published and version 4.2.19 now available. We will continue monitoring the issue while affected users are updating to confirm that it has been fully resolved.
Identified
We've received reports of an issue where some Android users cannot make or receive calls on their OpenPhone number. As this issue is affecting users on the latest version(4.2.18) we have halted the rollout to ensure no additional users are affected. We have redeployed the previous app version to restore calling functionality and are awaiting Google's approval.