In Asterisk SIP Settings, General tab, confirm that External Address is set to your new IPv4 address and Local Networks is correctly set. Submit, Apply Config, then restart Asterisk and test.
If you still have trouble, at the Asterisk command prompt, type pjsip set logger on sip set debug on
make a failing test call, paste the Asterisk log for the call at pastebin.freepbx.org and post the link here.