Canon EOS 80D (W), Instruction Manual, Page: 426 / 526

3
Custom Function Settings
N
426
C.Fn III -3 Retract lens on power off
This is to set the lens retraction mechanism for when a gear-driven
STM lens (such as EF40mm f/2.8 STM) is attached to the camera. You
can set it to retract the extended lens automatically when the camera’s
power switch is set to <
2
>.
0: Enable
1: Disable
C.Fn III -4 Custom Controls
You can assign often-used functions to camera buttons or dials
according to your preferences. For details, see page 433.

With auto power off, the lens will not retract regardless of the setting.

Before detaching the lens, make sure that it is retracted.
With setting [ 0: Enable ], this function takes effect regardless of the lens’s
focus mode switch setting (AF or MF).