Count repeat instances specifies whether repeat instances are counted in reports or projects. When activated, this setting treats multiple consecutive page views to the same page as multiple page views. When the setting is set to “Off”, those page views count as a single page view. This setting affects only certain metrics, such as Single Page Visit.
In Reports & Analytics, this setting is not configurable. Repeat instances are included by default.
In Workspace, you can choose to include/exclude repeat instances under Project > Project info and settings. They are included by default.
This setting does not apply to Flow or Fallout visualizations. In Workspace, Flow has its own setting for removing repeats. In Reports & Analytics, the Flow report has always removed repeat instances by default.