Resolution: Not a bug
The links on 3.6.2 and 3.6.2+ for both tgz and .zip files does not appear to be the correct file. and on different platforms (Ubuntu 16.04 server, Ubuntu 18.04 desktop and Macbook Pro laptop) the md5 message digest is different for the same downloaded moodle archive.
On this main moodle download page for the current versions, the icon to click and download has a URI of:
and similar for the .zip for both 3.6.2 and 3.6.2+
These files, according to my unzip and tar commands, are not even a archives files.
After much trial and error I found the solution was that the links are forgetting to adda directory in the absolute path. The files that match the provided message digests actually reside on a path that includes the ... /direct/ ... in the path name like this:
p.s. This has nothing to do with the issue I voted for and started watching, but there was nothing similar to my issue.