Surely $CFG->wwwroot should be 'https://developmenttest-▮▮▮▮▮▮.msappproxy.net'? A Moodle site can only have a single URL: the URL used in the browser to access the site and presumably the .local URL isn't that URL.
Depending on how the Azure application proxy works (I'm not familiar with it) you may need to add $CFG->reverseproxy = true to config.php. If you're getting a message like "Too many redirects" try this. If you get the
error "Reverse proxy enabled, server can not be accessed directly" then remove this setting.