It still looks as if the remote host doesn’t accept the ssh key for svc_foreman. Check the log on the remote host for details.
You should be able to check this on the main server (or from the smart proxy in case the connection comes from a proxy and not the main server):
[root@foreman ~]# sudo -u foreman-proxy ssh svc_foreman@remote.example.com -i /usr/share/foreman-proxy/.ssh/id_rsa_foreman_proxy.pub -v
That should work. If not and you are using IPA or otherwise the sss_ssh_knownhosts_proxy or other ProxyCommand settings, the topic All remote execution jobs fail immediately with exception may help.