PWA disappeared on my site

We successfully used PWA on our site up until a couple of months ago when the option to download the app just didn’t appear on mobile. I’ve went through the PWA settings numerous times but don’t see anything wrong at all. Need urgent help.

The debug links all seem to work except the offline page gives a “We were unable to load the page you requested.”

Please help. If you need more information please let me know what you require.

The page I need help with: [log in to see the link]