Why? Do I need to do something special on server1?
Is there any multi server documentation yet? I havent found a primer on how it is supposed to work.
Please make sure that you use the same ispconfig version on both servers. So as you use 220.127.116.11 on the primary and then reinstalled the secondary, I guess you used 18.104.22.168 on the secondary and this will not work.
1) Uninstall ispconfig on the secondary.
2) Update the primary to 22.214.171.124
3) Install ispconfig on the secondary again in expert mode.