Zend certified PHP/Magento developer

“Create Permanent Redirect for old URL” is greyed out but checked, why? how?

Background: I have tried to bulk update attributes for my product but it fails.
After digging around I can see that when I open a product for edit, “the Create Permanent Redirect for old URL” is greyed out, as it should be since no change has been made, but it also is checked, which it should not be. Saving the product in this condition will fail.

I can manually get around it by changing the url key, which un-greys it, untick the box then change the url key back – but it is not feasible to go through every single one of my products to do this!

The status of this is controlled via knockout data-bind

data-bind="attr: {id: uid, name: inputName}, value: value, disable: disabled, hasFocus: focused, simpleChecked: checked" 

Where does the status of that box come from? Is that coming from my product data somehow or an option somewhere? It certainly should default to disabled, not checked but here it does not.

I know very little about that part of the system but where should I start looking to I find what module, code or data or setting is causing this simpleChecked: checked?

Also since I have the same problem with the bulk update can it really be so stupidly interface related, does bulk update simulate an admin edit?

Looking at the network I can see a request for Magento_Ui/templates/form/components/single/checkbox.html which is indeed both checked and disabled

Is it normal that this box is that way and it should just be ignored unless the url key changes, and my bug is that it is not ignored?

I am not even sure what the bug is, but I know bulk updates fail

Does it mean that something should then process the form and correct it, and this is what is not happening?

I do not understand enough what is happening here and so pointers where to start looking would be most welcome.