Canon eos 6D buttons not working constatly trying to focus

Hi, I have a problem with my Canon 6D. It was working fine and one day when I turned it on it started this behavior: when turned on it starts focusing but no buttons are pressed, Top lcd shows information as unusual, AF mode, Drive, ISO buttons not working, only backlight button works, shutter button works...

I've tried reset it by removing battery and card with no succes, even tried removing internal clock battery and cleaning all the buttons, nothing changed, tried top cover with all buttons from another 6D still same results, I think it's corrupted software or motherboard issue it is running firmware 1.1.2 I've tried update with EOS utility because usual method with SD card is not possible because menu button doesn't work as well but in EOS utility I get a error message "update not possible, camera busy"

Has anyone had similar problem or know how to "force update" it?