I have been using graphine for 6 months and have had this issue once before with trying to download an app on google play store it just finishes download and then just goes back to install button as the app hasn't been installed Wonder why this is with a specific app I have on many profiles won't download now for new profiles. Tried rebooting didn't work
Sandboxed play
With this specific app, had you installed it from another source in another profile? Like, for example, one profile installed app xyz from F-Droid and another from Google Play?
I've had this happen to me before as well. I also didn't get an error message, but the error was caused by conflicting packages, signed for different repositories.