Hey everyone,
Not sure if you guys have figured out a way to stop the pop-up notifications but I came across an app that helps sort this issue out (at least it did for me
)
"Step 1: Install HeadsOff
Go ahead and install HeadsOff, Jawomo's app, from the Google Play Store for free. Obviously, you'll need to be running Android 5.0 or higher for this.
Step 2: Enable the Service
To get this application working, open it up and select "App is disabled," then enable Notification access. Once access is granted, heads-up notifications will be suppressed.
Step 3: Apply It on a Per-App Basis (Optional)
With the Pro version ($1.99), you can enable HeadsOff on a per-app basis so you don't miss out on the alerts you really want. There's also an option to select how notifications appear on your lock screen, but this can also be done natively through the stock Settings app."
Hope it helps!