2 year old awful sleep

[Anne8888]

Since DS turned 2 (now 2.5 months) his sleep has been awful, he was such an amazing sleeper up until then. Its been on and off for the past few months but he has started waking multiple times in the night and wants to start the day at 5am. I started silent / rapid return last week, the first night I must have returned him to bed at least 100 times and it took 1hour 20mins whereas last night it only took 4 times so there is definitely some improvement. However, it seems to take a lot longer when its my partners turn to put him to bed but I think that is because he use to lie with him on the floor until he went to sleep so maybe he see's him as a pushover and he also gets stressed 10 minutes into the silent return so maybe DS senses that? I'm just looking for some reassurance really.. how long does silent return take to work? Is it normal for him to be so unsettled and multiple night wakening's? I miss the nights where we would took him up in bed and he would go to sleep on his own, its just a battle every night and is becoming really draining. He also tries to delay bed time every night saying his head, hand, foot etc are hurting and that he's done a poo poo when he hasn't!

As it has been on/off, perhaps a sleep diary would help identify the root cause?
Note what he did and ate in the day and then how well he sleeps. For example, an overtired child will resist going to bed at that age. Or a child that has too many naps or had a bit of caffeine/sugary dessert will not be tired. It could be as simple as the days are getting longer and he needs his room to be properly dark to trigger sleepiness or stay asleep (this could explain not going to bed before 9pm as it’s still getting dark at 8pm now, and the 5am wake ups as it gets light now at 5am with sunrise around 5:30am if you’re in the U.K.).

The silent/rapid return assumes there is no reason for his poor sleep, but usually there is a reason.