Hi Michael,
What exactly does "IPsec SA: unsupported mode" mean? unsupported mode "transport"?
You are using the kernel-libipsec plugin, which implements IPsec in userland and requires tunnel mode. You probably don't want to use that, see [1] for details.
Regards, Tobias [1] https://docs.strongswan.org/docs/5.9/plugins/kernel-libipsec.html
