In the admin panel Template Path Hints can be enabled at the store view level at all store views except one. In that particular store view the options are greyed out, including the "Use Website" checkbox.
How to troubleshoot this? The site is in developer mode and cache has been cleared. I have also tried manually setting the values (and unsetting) directly in the database. The path hints are shown on those other store views on the frontend but not this one store view - and despite being set in the DB they still show the wrong value and are greyed out in the admin panel.
It is Magento 2.2