Toddler waking 4:30am

[Mazzatron]

My toddler has been having a very bad patch of sleep the last 3 or 4 weeks. It's starting to get better now, he's now sleeping through the night again but waking at 4:30 consistently. He seems very tired from this so I don't think it's because he's getting too much sleep. His room isn't too cold and it's pitch black at that time. He's eating well so I don't think he's hungry and I evidence of teething (we are waiting for back molars).

His speech has developed quite a bit in the last week which i think could be part of the sleep disturbance?

What could I be doing to encourage him to sleep longer in the morning? He is 23 months.

My dd is 23 months too and we’ve been in this 4am hell for about 5 months now. She used to sleep 7-7 no issues then this 4am waking started.
She wakes up and occasionally goes back to sleep in bed with me but more often than not gets home for the day.
She also sometimes wakes around 12 and stays awake for 2/3 hours it’s absolutely awful 😭 I work 12 hour shifts 3 days a week so I’m exhausted all the time.
I’ve tried everything and nothing seems to work so I’ve just sort of got used to it now hoping one day she will go back to sleeping well.
If she gets up at 4 she’s usually asleep on the sofa by 6 so she’s clearly not ready to get up. She then naps for her usual nap after lunch around 12.30 and I wake her if she isn’t awake by 2 at the latest.
Bedtime is between 7&8pm depending on how tired she seems.
I do wonder if she wakes up cold but I can’t set my heating to come on in just her room so I’m going to have to try it on in the whole house and see if it helps at all.
Me and my partner are so exhausted, we have 2 dogs who need walking daily which is hard on little sleep. The housework is suffering as we are both so tired from working full time too.
We’d like to have another baby but I’m not willing to TTC until DDs sleep is a little better, apart from not wanting a newborn with a toddler who isnt sleeping well I also have zero energy to Do the deed 😂