The problem is that when you return to the Floor Plan, the layer shows.
See, Drawing that is placed on that Layout has a source. That source is a View. Now, Views are found in the View Map part of the Navigator. The Floor Plan is a viewpoint. If you save a View, that will be a viewpoint with specific settings, including scale, Layer Combination, Pen Set etc. The source of a Drawing placed on a Layout is always a View, never a Viewpoint. In other words, its source is a View of the Floor Plan Viewpoint located in the View Map, and not the Floor Plan Viewpoint.
So you will have the find in the View Map the View that is the source of the Drawing and change the settings of the View. Or save another View and place that View onto the Layout.
If you select the Drawing on the Layout and go to the Drawing Settings Dialog, it will tell you in the "ArchiCAD view" filed of the Identification panel exactly where in the View Map the source View of the Drawing is located.
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