If you want your root domain to be the default, you have to use a flattened CNAME configuration. I do this rarely on Cloudflare, you’ll have to check to see if AWS supports it.
I Ad the same problem, you have to change of registrar to solve this issue, in France some support it other don’t, you need to contact support to be shure before making change.
Yep if you really want the root domain as the default, you’ll need to use a different DNS provider. Cloudflare’s is phenomenal, and free. I use it for all of my clients.