Hello
The Sonos App refresh in May 2024 brought significant changes/improvements relating to App Navigation or User Interface (UI) . Granted “improvements” may be debatable depending upon your then and now comfort level to proficiently navigate the App. This Tutorial is not about missing features; which to date are few compared to almost a year ago, but more about App UI (as was stated at the beginning).
Disclaimer: This is a community member authored tutorial. This is not an official Sonos authored tutorial/document; nor is it supported by Sonos Customer Service and/or Tech Support.
Selecting a room other than what is showing in the “Now Playing” section at the bottom of the App upon opening is not as difficult as you might think or have experienced. Here’s how it’s done in 4 easy steps without stopping the activity in another room.
In Image # 1 below you see that the room “TV” is in the “Now Playing” box at the bottom circled in Red. At the top you see the “Drop Down” arrow circled in Yellow. Taping the arrow will reveal all my rooms as you’ll see in Image #2
Image #1

Image #2
In this image I’m going to select the room “Fireplace” circled in Yellow.

Image #3
In this Image you see that “Fireplace” is in the “Now Playing” box circled in Red; but has no active content. I’ll next select Apple Music circled in Yellow as a source.

Image #4
As you can see Fireplace is now the active room in the “Now Playing” box.

Image #5
In this slide you can see by the activity bars circled in Yellow; both rooms (Fireplace and TV) are active!

Manufacturer changes are inevitable for hardware, software and applications. Sonos has made changes to its App before prior to the May 2024 release. The major difference (IMO) was that those changes were gradual verses all at once. However, even those changes required a slight learning curve.
The vast majority of people don’t like change. Granted what may seem easy and/or straightforward to some may not be the same for others. Hopefully, Sonos has learned that implementing sweeping changes all at once is most likely not the best course of action.
I hope this information helps to allow you continued enjoyment your Sonos!