Student Premium, USA

iPhone 7/Apple Watch Series 3

iOS 12.1.4/watchOS 5.0.1

I recently got a replacement iPhone 7 and loaded a backup of my old device onto it. When I played music on my old iPhone (also a 7), the watch app would automatically open and show me what is playing, with the ability to change the volume, skip the song, etc. After I setup my new phone with the backup from the old one, the watch app does automatically open when I play music, but it is essentially a blank screen. Where the song title is displayed, it says "Spotify" and the artist is "peteroleum2's Apple Watch," and none of the other screens have any function.

I'm just wondering if this is a function of the new phone/watch not recognizing each other or something like that, or if it's software related and if it's as simple as deleting and reinstalling an app. Thanks!