Hi! I'm new to your group, I started with a single site: votre.fashion and my company was happy with it and wanted me to make more. I started in an AWS LightSail Bitnami single site image. I've setup multisite in an AWS EC2 Bitnami multisite image. I'm working on setting up DNS correctly and 3rd level domains and I've got some setting wrong somewhere. I can get to the main site, but any 3rd level site will not work.
I believe it's an interaction of Route 53, Bitnami and basic MU setup (Sunrise?) but I can't nail it down.