Help with ActivityStarter and file access

So I have an app which produces a table of insulin doses and saves it to the app's application-specific directory as a CSV file "FullInsulinScalex.csv"; this works fine. I can share the file from the app with the usual email and text apps no problem.

But I thought it would be handy, since many people can't navigate to the ASD with the default Android file manager, to have a button that opened the CSV file in Excel or Sheets, if either had been loaded on the device.

So I made two ActivityStarters, and after much fiddling, they both work flawlessly in AI Companion, opening the correct file in the in the Companion's ASD with the respective app. But when I make an APK and load it on the device, it won't work. The "ResolveActivity" is empty.

It seems like maybe these called-up apps can't access my app's ASD? I do know that if open Excel or Sheets on my device, I can't navigate to my app's ASD.

But I made a third ActivityStarter using SolidExplorer, a file manager that can navigate to my app's ASD. Again, this worked fine in Companion, but not at all with the downloaded APK.

Here are the blocks for the buttons:

I'd be very grateful for any advice on what I might be doing wrong, or other ways to diagnose the issue.

The clue is in the name - App Specific Directory. Android security measures ensure that only the specific App related to the directory has access to it. Of course there are probably hacks, but that's not our department.

If you really need to present the data in a spreadsheet style, you can do so within your App. Probably the easiest way is to build an HTML Table on demand, save that to the ASD, and display it in a WebView Component.

Thanks, I was just confused that it worked for the Companion's ASD, but maybe it has different permissions.

Most users will want a CSV they can share to email, but I guess I can also give them the option of viewing on-screen with WebView, thanks for the suggestion.