Alright, since I started this thread, I thought I’d contribute my own fix, which is for WIN 10. This is for creating new sites if you are not being successful. (or reconnecting old ones from Local Sites with their structure intact)
NOTE. The method above was done with Fast Docker Volumes and IPV6 Loopback turned off. When I tried enabling FAST DOCKER VOLUMES and IPV6 LOOPBACK on this after the sites were up and running, it created a non-stop loop of restarting the running websites, so I had to eventually EXIT the app. When I tried the sites again, I was back to 502 Error. I had to EXIT again. This time after restarting the local machine, they were working again, with Fast Docker and IPV6 Loopback enabled. Not sure if I did something wrong here by turning on Fast Docker WHILE some sites were running or if this is part of the bug…
I have left Fast Docker and IPV6 on for subsequent site creations/reconnections since I will be using these features. That was not an issue but I still had to use the above fix, regardless of whether the site was being setup with these options enabled or disabled.