i know I'm not answering the specific question, but just noting that I have found that the later in the day I exercise, the worse I sleep (my tai chi teacher says it arouses the chi, but perhaps there is a more western / sport science explanation as well!!), and have also increased my exercise significantly due to diabetes.
Metformin has been playing tricks on me too, seemed to have settled down after a while but now seems to have left me rather intolerant to any oily foods, which overall is no doubt a good thing but is also yet another factor to be precious about!
good luck with your tests, hope they find something simple to fix.
bruce