I was looking to see if anyone outside TMS had tried it.
After testing on Android and iPhone, Save to Home Page is the way to do it. On Android (Brave / Firefox) it then asks if you want to install or Add a shortcut. Install works. On iPhone, just saving works.
The PWA I wrote 2 years ago as a demo, works fine offline.
A simple dummy one I wrote with current tools, works fine offline.
A more complicated one I wrote to demo the concept to the client does not even load the first page, when offline. There are no errors, so its a bit difficult to figure out. My current suspect is that it hasn’t saved the css file or logos.
If it’s any help I have used TMS WEBCore for various projects including a PWA (this was a demo project, but it was a working demo).
If it’s not displaying on start-up, I am going to guess it’s something you’ve done in the app itself - the framework is pretty much the same and just does a simple wrapping with the required web worker type stuff.