Check the live source
Confirm the exact QuickDesk snippet appears once in the published page source, close to the end of the body. A tag visible only in an unpublished template cannot load.
Check site matching
Compare the browser address with Where chat appears for the selected site. Protocol, hostname, and path rules must describe the page being tested.
Remove local interference
Try a private window with extensions disabled and reload after saving widget settings. Then inspect browser errors and record the page address and time if support must investigate.