Our little boy is 4yo and will be 5 in July. He's never had any problems with sleep until he started school in September. He's gone from sleeping through 7-7 to waking multiple times during the night. Some nights he can wake 3 times even before 12pm and he seems to wake like clock work every 3 hours. He will lie there shouting myself or my husband. We have to sit in his room until he falls back to sleep which can be around 10 mins and we have to sneak back out the room. He has white noise on during the night as noises seem to affect him. I've spoke to sleep consultants on Instagram who say it's due to cortisol. Does anyone have any advice as we're at our whits end on what to do?? Thanks x