Azure VPN Ipsec Tunnel keeps dropping

I have followed the instructions on how to establish an Ipsec tunnel from a Balance 380.

I noticed the connection is unstable. The connection keeps flapping for no rhyme or reason. Nobody is in our office so there isn’t much traffic being passed from our onprem network to Azure, in fact the tunnel will continue to flap overnight. There isn’t a consistent time frame for uptime.

Anybody know what might the issue might be?