I ran into one problem on pure android 9: if the app is signed with a real key and is not installed from the Play Market, then the app shortcut is not created and it can only be launched from Explorer. It feels like you need to add special tags to the manifest. If so, which ones?
Everything is fine in the app list. You can start it via CX Explorer. The shortcut was created in the shortcut Creator. I just experimented in MIUI before and everything was fine there and did not depend on the Play Market, the problem with the shortcut appeared only on naked android 9