I have one domain with an SSL certificate (storewebsite.com)
I also have little individual sites for different clients.
In Magento 1.9 all I needed to do was go into the web settings and set
Base_url : http://teamname.storewebsite.com
Secure_base_url : https://storewebsite.com
Use SID on storefront : yes
These settings allowed my customers to shop on their own personal site and then go through checkout on the main domain with an encrypted SSL connection.
Problem : In Magento 2.1.5 when I try to go to checkout and get redirected to the main domain the cart is empty. I can go back to the subdomain and the items show back up.
Question: Does anyone know how I can get my items to keep on existing when going to checkout on the secure domain?