Hi @enryls !
I ran into EXACTLY the same issue yesterday.
Using an ECS Service with application load balancer. Until here everything works fine, but adding the Cloudfront to it results in the “Please Wait” endless loop.
Could you already figure it out? I’m thinking of cashing issues and a mismatch between Streamlit and Cloudfront settings, but was not successful until now… 
Cheers, Astrid