I have an non-Play Store application, that I need to deploy to several thousand devices. Although I have a Restrictions profile allowing non-market app installation, I'm seeing a prompt on screen from Play Protect for each install blocking the installation. If I click the ' install anyway' option the app installs fine. But obviously that's not a solution for deployment to thousands of remote devices. So, I either need a way to disable Play Protect (seems unlikely from what I've read so far), or a way to while-list the application. Ultimately, the solution may be to get the app developer to properly publish the app to the Play Store.
That is also probably why play protect was objecting since it does not object to just installing a normal app from an apk, also yes they never should have distributed it like that, to the point where if they refuse to fix it you should drop them that is something that should never happen.