Damn, thats a bummer
I sleep like a baby - and almost immediately and longer, if I've been out many hours.
Of course, I have to "do something" totally different, or relaxing, for a couple of hours if coming home late in the evening and still on an adrenaline kick, high after an awesome session that has not settled fully yet.
But when I hit the sack later, I sleep even tighter than normally.
Very interesting what the reason/cause could be when it does not work like that, as it seems you are not the only one having trouble sleeping, so you are right, it COULD be something that has been diagnosed before and maybe quite common ?