It seems all the pop ups are coming from Google Play advertising a product (Pixel 3 comes up constantly) or an app to install: New York Times, AARP.... Some are pretty intrusive. I was watching a vid on instagram and a pop up video for AARP overrode the video I was watching. This wasn't part of the original video because I was able to clear it and continue watching the one from instagram.
This is just beyond annoying. Again, all this happened after downloading messenger +. I'd really, really like to keep messenger + as I love using it and I've already synced it up with my other devices but not if it comes at this cost.