6 year old DS waking at 2am and can't settle himself back to sleep

[2sugars1milk]

My 6 year old DS shares a room with his twin brother. He has always been the lighter sleeper of the two. He woke in the night age 2-3 but improved from 3 years old. He has recently started to wake at 2am every night for the past month. He calls out for us and we go and settle him. I struggle to get back off to sleep (also a light sleeper) so DH and I try to take turns in getting up.
Sometimes it's a bad dream but more often than not it's just that he can't get back off.
I feel like it's a habit now and it's affecting his behaviour in the day.
We have a quiet bedtime routine (bath, milk, lavender, reading, cuddle and song) then he goes to sleep pretty well.
Do I sleep in their room for a few nights to break the pattern? We have a sofabed in there. I've done it before and he stirs and looks up in the night to check I'm there then he's straight back off to sleep. We are all like zombies in the day atm and I just want us all to get enough sleep (especially DH who is dealing with his mother's illness at the moment).

Yes I would do as you’ve suggested OP. Especially as it’s worked in the past. He might be picking up on the stress about his GP’s illness. Hopefully it’ll settle down again and he’ll grow out of it eventually.

If there is a relative who is sick (is it DS Granny?) currently that might be why your DS is worrying. He's checking you are OK.
If it were me, yes I'd go in and sleep on the sofabed.
Separation anxiety is not about the child feeling alone, it's about the child needing to control the parent's safety. At age 6 kids start to become aware that people can get sick or even die, especially if they are old.
Before sleeping on the sofabed you can try reassuring him when he's going to sleep, and include where you will be and what you will be doing... as a sort of bedtime 'story' you can go around the people in your immediate family saying 'twin brother is safe and sound, I am safe and sound, DH is safe and sound, you are safe and sound, now I will be safe and sound on the sofa downstairs while you go to sleep, then in a little while I will go off to sleep safely tucked up in my own bed. And we'll all have a lovely sleep'.