There could be several reasons why your phone is randomly blocking contacts. It could be a software glitch, a setting change, or even a result of a third-party app. To resolve this issue, follow the steps below:
Restart your phone: Sometimes a simple restart can fix the problem.
Check blocked contacts: Go to your phone settings and look for the blocked contacts list. If any contacts are blocked, unblock them.
Update software: Make sure your phone is running the latest software version, as updates often fix bugs and glitches.
Reset network settings: Go to settings and select "Reset Network Settings." This will not delete any data but will reset network-related settings.
Uninstall recently installed apps: If the issue started after installing a specific app, try uninstalling it to see if it resolves the problem.
Contact customer support: If none of the above steps work, reach out to your phone manufacturer's customer support for further assistance.