The stats functionality interface doesn't all work well on the Android client. If you're on a channel and turn on stats and then go to another channel, the stats don't stay on. However, if you go to turn the stats on, the check mark is already selected so you have to effectively uncheck it to turn stats on the second channel.
Also, I think it would be helpful if once you turn stats on, they stay on until you turn them off regardless of whether you change channels or not. This helps when testing antenna placement to see signal strength.