I’ve seen this pop-up before on my android phone. I think it’s something to do with your app (i’m not sure from your screenshot whether that’s a browser or a client app like Sync) not having permission to access your media files. You might be able to give that app media/file permissions in your phone’s settings and that will stop happening.
I noticed the same thing. It might be hidden due to anti-features. I found it on NeoStore.