Solution
When [Shooting modes] is set to the ⋖Auto⋗ () mode or the ⋖Handheld NightScene⋗ (
) mode, [IS-Mode] is set to [Continuous].
In the ⋖Auto⋗ () mode or the ⋖Handheld NightScene⋗ (
) mode, the [IS-Mode] item is not displayed on the Menu screen, so the [IS-Mode] cannot be set. (Even the [Off] setting is not available.)