GET on ANY container with an index.html returns HTML, not Turtle #1264

Please describe what you did in reproducible steps

Performed a GET on https://jeffz.solid.community/ (5.x) and on https://jeffz.solid.openlinksw.com:8444/ (4.x)

How did it work with 4.x series servers?

The GET returned Turtle

What happened when you tried the same with the 5.x series server?

The GET returns HTML

Any material that will help, logs, error messages, etc.