Having trouble configuring SD-WAN with IPsec VPN

Hello:

I've been trying to build SD-WAN with 2 site-to-site IPsec VPN connecting HQ and Branch office. I use FortiGate 60E in both HQ and branch office.  I setup my 2 VPN connections and they are working properly, but once I add them to the SD-WAN interface, the VPN connections stop working even though the SD-WAN interface appeared to be up but no ping can go through.  I configure everything in Web GUI, but I'm wondering is there some config I have to do in CLI to make it work? I heard it's very easy to do this type of config in FortiManager, so do I need FortiManager to push this type of config?

Thank you.

Best regards,

James