About the kernel: I'm using stable 5.3.9-3 on all of my boxes. I leave kernel 4.12 instantly when I install a new Leap and go for the current stable kernel immediately. This might be the difference. I can only assume Solaar is simply displaying what it gets from the kernel or the receiver or the battery measuring piece in you mouse. In my devices using the newest stable kernel the values were always reliable! Best regards Ralf