@thunkablestaff. I have solved the issue of websites not displaying in the webviewer component. It would appear that https or port 443 is hard coded into the request used by the viewers on the thunkable web page and companion but the programmed protocol is used on devices. I found this out by enabling https on my webserver and now everything works as it should.
Do you think this should be corrected so that previews and tests use the protocol as defined by the author in ALL cases? Interested to hear a reply from anyone!