When she opens the link, it correctly takes her to firefox, and gets to the app. But if she copy/pastes the URL into chrome, she gets the google page with the error: Your search - scrutineers.glideapps.io - did not match any documents. I’ve asked her to try to use https://scrutineers.glideapps.io, but she gets the same error.
If I do a Google search for “scrutineers.glideapp.io”, I get what you describe. When I paste it into the address bad, it loads the app. I suspect your client is searching for the URL on Google, not entering it correctly.