Canon EOS M6 - Custom Settings

[Canonm6]

I'm new here, and am looking for some help.  I just bought a new EOS M6 and Im having trouble with the custom settings.  Whenever I set custom functions for some of the buttons and dials, the camera "forgets" my custom settings when I remove the battery during a battery change. 

For example, if I set the mfn button to "record video", the setting will remain as long as I do not remove the battery.  If I take the battery out even for a short time during a battery change, the camera reverts to it's factory default.  The strange thing is that the problem only exists with custom functions.  The settings date, time, name, etc. remain.  Only the custom functions revert. 

Can someone tell me what am I doing wrong?

Thanks.

[alexpilion]

I tried on my M6, firmware 1.0.1 and the Custom Shoot Settings(C1, C2) are kept when I change battery. Be sure you saved the settings again after changing, since mine camera, and propably the default, is to to have "Auto update set" on Disable.
So the complete procedure is:

1) set the mode dial on the Av, or whatever you want to use as departing model for you custom shooting  setup.

2) change the settings

3) use the menù button and enter the "Custom Shooting Mode (C1,C2)" menù, it is under the 4 group of the wrench icon.

4) enter register setting and choose C1 or C2 to save the configuration.

5) eventually set "Auto update set" to Enable, this in case you operate the camera on C1 or C2 should save any change you make.