@Dave711 

Are you able to Ping the ER605 from the VPN client? Maybe try web browser incognito mode?

You can try Omada Controller. I'm using Omada Software controller and I can access local Omada controller from VPN client.

  @Somnus Yes, I can ping.  Incognito mode does not work!

  @Dave711 

I can confirm that this not work, only blank page.

I have to access router on wan interface and I cant use https, only http work.

You can enable remote access in admin setup and give access from a ip or 0.0.0.0, for security I have access only from a IP address

  @Dave711 Here is a crazy scenario. So after creating the IPsec vpn connection and being unable to load to the Management Console login page. I created a OpenVPN (Sever) and I'm able to load the login page as expected. If I then disconnect the OpenVPN session, access to the Management Console is maintained over the IPsec tunnel - ambit the is a initially a slight delay. 

I Still haven't figured out why the Management Console login page isn't available over the IPsec VPN.