More likely an "old" issue...I have the same one...

 

"HARLEY HIP" the stock seats are too wide in the front and when you put your foot down your groin stretches open that's what i found to be my issue .when i installed a solo seat (danny grey) i don't have that pain

 

When I got a custom 2 up seat that replaced my stock solo seat that all went away too. I`m 71.

 

With the factory cvo seat I had the same problem.
I had 2 issues that I was not aware of until later.
The seat pushed my legs outwards when I stopped. I went with the first reach seat, 1/2inch down 1 inch forward but the sides were less so I do not have to put my leg outward.
The second problem was the floorboard spacers. I added the 3/4inch spacers to push the floorboards out which again forced my legs outward. I removed them. I do not have it any more. I was like you I could ride all day without a problem but when I stopped my hips would like cramp and hurt like crazy.
Just a thought.

 

Jack Palance said "Gettin' old ain't for pussies". Thought it was pretty funny when he said that. Now - not so much.

Hope the new seat helps.

 

I think we can put it down to posture! There are several things that can combine to give us a problem like that. One of my BMWs did it to me every time I rode it. The problem with most Harleys is that they encourage us to sit very upright. That places our weight directly under the butt, rather than under our thighs. Your high bars add to that upright stance.

The most comfortable bike I have ever owned had me sitting leaning forwards a little, so my weight was under my thighs and my hands were fairly low. I would encourage you to consider making alterations to your bike, to see if small changes give you any improvement. Personally I would start my moving the bars away a little, if that is possible. Well no, I'd ditch them for a standard set!

 

I used to have the same thing on a different bike, tried a narrower seat and all was good.