Notification sound change won't stick

As far as I’m aware, no one is able to do that natively because Wyze hasn’t built that into the app, though it’s been a long-time request. Android users can do it with a work-around using a third-party notification interceptor app, such as Tasker, BuzzKill, or MacroDroid. The only one of those I’ve ever tried is MacroDroid, and it works, but there’s a bit of a learning curve to get it set up and working. You can search the Forum for guidance on doing this with one or more of those third-party apps. You might also want to take a look at these existing Wishlist topics (and search for others) and then vote and comment for those that are important to you: