Strongswan TS_UNACCEPTABLE – Troubleshooting TS_UNACCEPTABLE Error in Strongswan

I have a server hosted on ip <server_ip>
I have a personal computer at home, behind a router. The box public ip is <router_ip>. The client has a local ip on the router's subnet which is called <local_ip>.

Server is on ubuntu 18.04, local computer is on ubuntu 20.04. Each are up-to-date and installed strongswan using the following command

apt install strongswan strongswan-swanctl

Server got strongswan 5.6.2
Client got Strongswan 5.8.2

I created a CA, serv and enduser crt, using following commands with package strongswan-pki

ipsec pki --gen --outform pem > ca.key
ipsec pki –self --in ca.key –dn “C=FR, O=Test, CN=Test CA” –ca –outform pe > ca.crt
ipsec pki --self --in ca.key --dn "C=FR,O=Test,CN=Test CA" --ca --outform pem > ca.crt
ipsec pki --gen --outform pem > serv.key
ipsec pki --issue --in serv.key --type priv --cacert ca.crt --cakey ca.key --dn "C=FR,O=Test,CN=serv" --san serv --outform pem > serv.crt
ipsec pki --gen --outform pem > enduser.key
ipsec pki --issue --in enduser.key --type priv --cacert ca.crt --cakey ca.key --dn "C=FR,O=Test,CN=enduser" --san enduser --outform pem > enduser.crt

I modified nothing except /etc/swanctl/swanctl.conf on both sides

Server /etc/swanctl/swanctl.conf

connections {
    server {
        local {
            auth = pubkey
            certs = serv.crt
            id = "serv"
                }
                remote {
                        auth = pubkey
                        id = "enduser"
                }
                children {
                        host {
                                start_action = trap
                        }
                }

    }
}

Client /etc/swanctl/swanctl.conf

connections {
    client-server {
        remote_addrs = <server_ip>

        local {          
            auth = pubkey
            certs = enduser.crt
            id = "enduser"
        }
        remote {
            auth = pubkey
            id = "serv"
        }
        children {
            to-host {
                start_action = trap
            }                           
        }
    }
}

On server, I put certificates on the following places

/etc/swanctl/x509/serv.crt
/etc/swanctl/x509ca/ca.crt
/etc/swanctl/private/serv.key

On client, I got those certificates

/etc/swanctl/x509/enduser.crt
/etc/swanctl/x509ca/ca.crt
/etc/swanctl/private/enduser.key

Then I use the following command on both server and client

swanctl --load-conns && swanctl --load-creds

and on the client

swanctl --initiate --child to-host

But it fails with the following error on client side

[IKE] establishing CHILD_SA to-host{7}
[ENC] generating CREATE_CHILD_SA request 3 [ SA No TSi TSr ]
[NET] sending packet: from <local_ip>[4500] to <server_ip>[4500] (256 bytes)
[NET] received packet: from <server_ip>[4500] to <local_ip>[4500] (80 bytes)
[ENC] parsed CREATE_CHILD_SA response 3 [ N(TS_UNACCEPT) ]
[IKE] received TS_UNACCEPTABLE notify, no CHILD_SA built
[IKE] failed to establish CHILD_SA, keeping IKE_SA

Server side logs (using swanctl -T) are below

08[IKE] traffic selectors <server_ip>/32[tcp/ssh] <server_ip>/32 === <local_ip>/32[tcp/55592] <local_ip>/32 inacceptable
08[IKE] failed to establish CHILD_SA, keeping IKE_SA
08[ENC] generating IKE_AUTH response 1 [ IDr CERT AUTH N(MOBIKE_SUP) N(NO_ADD_ADDR) N(TS_UNACCEPT) ]
08[NET] sending packet: from <server_ip>[4500] to <routeur_ip>[59527] (1184 bytes)
16[NET] received packet: from 86.234.97.45[59527] to <server_ip>[4500] (256 bytes)
16[ENC] parsed CREATE_CHILD_SA request 2 [ SA No TSi TSr ]
16[IKE] traffic selectors <server_ip>/32 === <local_ip>/32 inacceptable

Can anyone explain to me what I did wrong ? As I thought TS should be automatically negociated