Stale Connections - PPPoE disconnect Causing Timeout

Hi,

When my PPPoE drops then connects again, my ip address changes.
As a result, I am no longer able to connect to my VOIP provider (Nexmo). It says time out and retries every 20 seconds (asterisk)

When I Iook in the connections tab on winbox I see that the “reply destination address” is wrong for that particular connection. It is still using the old IP given by my ISP as the “reply destination address” and says will timeout in 59mins. But whenever asterisk retries (every 20 seconds), the timer resets and goes back to 59mins again.

Asterisk is able to connect again if I delete that connection.

Why is that connection not dropping on its own? How can I clear those connections when my PPPoE disconnects.

If my explanation is not clear, please have a look here: https://forum.pfsense.org/index.php?topic=18053.0 I am experiencing 100% the same issue.

Thank you for your time.