Like you, I find I can't stay sleep the night after a rest day. I've started substituting other activities (weights, swimming) in the days where I don't ride. It's not a true rest day, but I'm working different parts of the body.
I find that I easily get over trained and don't sleep, and conversely, if I've been riding a lot then stop for a day, I'm also going to get terrible sleep. If I take a number of days off in a row, my sleeping comes back though. Hair trigger sympathetic system I guess. Doesn't help that I have a lot of work stress on top of the training/physical stress. I look forward to retirement in that respect, but still have 10-15 years on that front.