You take a totally different approach if you are sewing a skirt to a scrap waistband than if you are sewing it to a visible waistband.
With a scrap waistband, you sew the skirt to the waistband, then set the waistband inside the bodice and stitch in the ditch of the piping.
With a visible waistband, the waistband is actually a part of the bodice, and usually the lining is the complete length, the waistband being essentially a decorative pieced element of the fashion fabric.
That means it isn't used as a utility piece to set the skirt to; you have to set the skirt directly to the bottom of the waistband/lining in situ, just as you would on a dress without a waistband if you chose not to use a scrap waistband.
With this dress with a visible waistband from Vintage Textile...
...you can see, on the inside, the stitching where the top of the waistband was sewn down when it was applied to the full lining; the bottom was piped; and then the skirt was set directly to that bottom edge.
Less commonly, as in this example from Ebay...
...the waistband and its lining have encased the fashion fabric and its lining at the bottom, but still the bottom edge of the waistband has been piped and the skirt would have been directly attached to that bottom edge once the bodice was complete.
Clear as mud?