Can't make a global color swatch of an already tinted swatch

I used to be able to create a global color swatch, then set that color swatch to a certain percentage (tint) and then make a new swatch of that. That way, I could quickly choose a tint of my swatch without going to the original swatch and fiddling with the tint slider. I could also then set a tint of THAT swatch. Now when I try to do that, I can't make a new swatch of a tinted version of a swatch. It doesn't give me the option to create a new global swatch of the tint; it just adds a duplicate of the swatch to the palette (first attached jpg...it's showing the tinted swatch with the original swatch to the left, with duplicate version of tint swatch). When I click on the color palette flyout and click on the color tab, instead of seeing my tinted color at 100%, I see my original swatch with the percentage of my tint (second attached jpg). In years of working with Illustrator, I've never had this problem. Does anyone know what's going on?