Sorry for this - first, let's try the steps listed at this link: https://videostream.freshdesk.com/support/solutions/articles/5000050849-premium-is-not-detected.
Second, if the first step does not work, I need you to go to your Google account settings, shut off permissions for Videostream (https://myaccount.google.com/permissions), then log back after you remove and redownload the app.
Third, if you purchased through Google Play, see below:
"If you purchased on Google Play, you need to simply connect your phone to your PC on the Videostream app (the app needs to be open on both devices so that your computer can 'recognize' your phone and the premium. Log in on your phone (which I assume is already signed in), then connect to your PC).
We did this so you can take Videostream premium everywhere (and because Google Play doesn't tell us who's purchased on their platform so we don't know who's a premium user (and therefore can't authenticate you) if you purchased this way, because yay that's fun)! You need to connect your phone every 30 days for your computer to remember you have premium."
That should do it! If not, reach out to us and we can put in a request to our dev to manually add you on our back-end - he's pretty busy though, so it may take a few weeks for this process to complete.
In the meantime, hope this resolves, and take care:)