Opnsense Static Route breaks ansible

[Maily]

Hi guys,

im using an opnsense (virtualised ) for 2 months and want to administrate vms via ansible which worked great before doing the switch from unif to opnsense.

After inserting OPNsense between my main LAN and a Proxmox SDN subnet, Ansible SSH connections started failing during SCP/SFTP file transfers with "Broken pipe".
MTU and routing are fine; talk "plain" ssh and sftp to this vms are working and vms in my main network are not affected.

Right now I have a static route from my LAN to the vm Subnet (Proxmox SDN) via Proxmox Host (as gateway for SDN traffic)

Also i noticed ssh connections to this subnet drops after 30 seconds but reconnect works imminently and after set firewall Optimization to conservative the issue disappeared

[Patrick M. Hausen]

You have a case asymmetric routing. Most probably.