I'm not sure if I've missed a setting, but when I create a subpage and check the location url in the location tab, the page is sitting in the root of the website rather than in the subfolder. This then gives the incorrect url for the template path.
Here are some screenshots of the page settings;
This is the parent page;
and this is the child page;
Which results in a path of;
I've tried adding the /specialist-sensors/ manually in the location tab with move to this location ticked. Which moves the file, but doesn't update the template url.
It's a site I did a few years back and if I add a subpage to a page I originally did it works as expected, so didn't know if I'd missed a step when setting up the new pages?