I read this :
It says babies at 5 months will change as their sleep cycle changes. In the early stages their sleep cycle is about 25-30 mins of light sleep followed by 25-30mins of deep sleep and the cycle starts all over again. But in the article it says at 5 months most babies' sleep cycle changes - they fully wake and need to be put back to sleep, either by self settling or by parents helping them to if they are used to carrying and patting or dummy during bedtime.
So for babies who used to sleep long stretches or sleep through at night before 5 months, they will start waking up very often.
Do you experience this with your baby? Was it really at 5 months?