The following seems to work if you're ok with the new taskbar and don't use "explorer patcher".
I checked task manager to see the difference between the (hard link) command line for the instance created by the control-panel method, (then closed that instance). Using task manager I ended explorer task which gives a blank screen (except for the task manager). start a new task using that command line and it works. Each instance of file-explorer now has the old ribbon.
BUT, this also knocks out "explorer patcher" so the task bar reverts to the new style, which is fine if you like the new task bar. Perhaps someone who knows a lot more than me can make use of this info and fix both.
Method: start taskmanager , end all instances of explorer, run new task with this command line:
C:\Windows\WinSxS\amd64_microsoft-windows-explorer_31bf3856ad364e35_10.0.22621.608_none_b3fd0d5042b63bbd\explorer.exe
I have no idea why this works. The only difference between the way explorer starts is instead of a hard link in the \Windows folder it is starting directly from the WinSxS folder.
Although this restores the ribbon it creates a bigger problem. On my system, it broke Task Mgr. The Restart tab is missing.