It isn't anything to do with the Beta software. Calls function is core and probably is one of only a few items that won't be touched for releases but will be tested as standard.
Is it SMS messaging or RCS messaging that's still working? If it's RCS then that uses a data connection rather than a network provider connection over which SMS messages are delivered. So if youre getting RCS messages and Internet then it would point to a network issue.
- Check SIM is enabled and that you've got signal.
- restart handset / switch flight mode off and then back on as this will force the handset to re-establish network connection.
If you're getting SMS then likely that you may have got call blocking turned on. Check
Call settings -> supplementary services -> Call blocking, and turn any blocks off.
In answer to your other question re. Battery life. I'd suggest clearing the system Cache (plenty of guidance on here and Google on how to do it). This may also resolve the call issues.
