I’m 64, and having similar experience with biking. BG used to always drop with aerobic exercise (I used to run, but then: arthritis), but now as often as not it goes up, though nothing like as high as you’re seeing (I’m currently at a 5.8 A1C, so I’m starting from a pretty low avg. to begin with). I always understood that high intensity exercise would raise it while slow-steady aerobic would not, and that’s always been the case for me, except for riding in very cold weather. Like you I’m wondering if aging and hormonal changes have something to do with it. I’ll be interested to hear what you learn about your cortisol levels.
