E-M5 a Lumix 20/1.7
To me it has not happened yet.
. . . I leave my sleep mode setting at 5 minutes, auto-shutoff at one hour and my 20/1.7 has never caused any of the problems that have been described so often here. I also still have the original firmware - 1.0. What I also do quite often is turn the camera off when I'm not actually using it. This is so habitual that it has almost never been in sleep mode AFAIK.