I take 3 Madopar (which is levodopa, like your Sinemet). I also take one prolonged release Mirapexin – a dopamine agonist like your Neupro patches.
Until a couple of months ago, I took the Mirapexin in the morning and my sleep pattern became chronic and, like you, I was falling asleep at all times during the day. Then, I switched it to the evening and the change has been dramatic. I can’t understand why, when it is supposed to spread itself out evenly over 24 hours, but there’s no mistaking that this was the cause of my night sleeplessness (which led to daytime sleepiness). You don’t say which time of day you replace your patch but could a switch to morning or evening help you perhaps?
I’m thinking that maybe it could be something to do with the fact that you use less dopamine at night. (Turnip or Kate would know.)
I hope you get sorted out.