Trying to make use of MS Kiosk mode and lock down systems that just need to run Edge or perhaps a few other applications. In locking them down to Edge they need to access a sharepoint URL.
If they log in with Kiosk Mode - the Sharepoint 2016 site gives an error - This operation has been cancelled due to restrictions in effect on this computer. Please contact your system administrator.
If they log in without Kiosk mode - no problem
Now - if they have accessed the site and later have kiosk mode applied - no problem.
So the error only pops should you use Kiosk Mode and then try to access the page for the first time. Once the error is "fixed" meaning you have visited the site with Kiosk Mode disabled, the problem does not return even for a new user on the same PC.
If you click OK on the error, the page proceeds to load fine. A new tab and trying the site will produce the error again. Other websites open fine.