There are two waterfalls to tune. I don't know why. You have to click the big lower one, then the smaller upper one. gqrx is much easier to understand. Looks like it works. Unfortunately, I can't hear anything. CubicSDR reports "no audio devices found!" Clueless! Software Manager, Synaptic, apt, dpkg etc should have fixed any dependency issues. Every other app I have ever installed or built could access sound. But, maybe it will work for you...
Installs super easy and works as expected. Similar interface to other packages. Worth giving a try. I'm running Mint Cinnamon 21.1x. Found USB SDR instantly and worked first time.