3yo started waking in the night - advice?

[Kri5ty]

Hi everyone

This one came as somewhat of a shock. DS1 had been sleeping through since 6 months old, he'd self settle etc and you could guarantee he would sleep 12 hours +

We had DS2 in May.
DS1 still slept through, and also started to potty train.

September we took the cot sides down
October he started waking 3/4 times a night. Anything from a wee (we put him on the potty when we come to bed), to needing to blow his nose (we put tissue in his room), needing his teddy, needing to be tucked back in... Other times he just waits for us to get up and put him back in bed.

We just put him in bed, and leave again so it's not just for attention.

I'm starting to think it's a habit, but I've no idea how to break it!

Any ideas?

Ps he has a glow clock and knows that yellow means he's allowed to get up