Rock Solid Site2Site crashed after upgrading from 18.5.3 to 19.5 GA on Both Sides

Hi,

I had a S2S VPN between a XGS2100 (18.5.3) and XG125 (19.0.1)

After upgrading both Sites for 19.5 GA the VPN connection crashes 2-3 times a week.
The VPN is up and connected, but no traffic is routed from S2S, only a manual disconnect and reconnect will fix this.

Where do i start to fix a random S2S VPN error / routing error / etc... ?

Can i switch strongswan into debug mode for a week and wait for the next bug?

Or is there any way to find this inside the normal logs?

Thanks

Jürgen