Applying a Gradient Across a Stroke

Bah, I finally figured this out.  Y'all were right about the appearance panel.  I just couldn't fathom what I could possibly be looking for there other than that yeah, it's a circle with a stroke, and when I was first looking, that's all I was seeing.  And I remade the circle so many times and with different details all to the same result that I was getting frustrated with being asked for screenshots of the circle.  BUT, it looks like the problem was that the stroke was defaulting to align inside the circle rather than centered, and apparently you can't use that button if the circle is aligned inside.  The pen tool work around was working because it was realigning the stroke as well as copying the gradient application.

For anyone else coming across this (and I've seen several posts asking for help on this but none with answers), the stroke has to be center aligned.  You can select that with this here.

And yeah, when I went back from scratch and did it again, I did get a clue in the Appearance panel.  Right there next to where it shows the width of the stroke it says "Inside".  My previous file didn't have anything there because I was looking after I'd already done the work around with the pen and eyedropper tools, and it doesn't say anything about the alignment at all there when the stroke is centered.  It normally just gives the stroke width, shows if there is a gradient, and if there is opacity. 

Oh, and it turned out that the gradient fill was irrelevant.  You can see in this one, I didn't even have one of those that time.  But apparently stroke alignment matters quite a lot for some reason.

Thanks to all for the help.  I would not have kept going back to the appearance panel after not getting anywhere with it the first time, if y'all hadn't been asking for screenshots of it.