14 month old waking frequently during the night

Hello!!
I’ve been having issues with my 14 month old son’s sleep - we have always had ups and downs in our sleep journey, but he was sleeping amazing at around 11 months and for the past 2 months it has been a struggle.
He is currently waking up multiple times during the night, immediately stands at the corner of the crib and it is difficult to get him to go back to sleep (we have to soothe, take him out, sometimes even give him milk). Because of his very interrupted sleep, he has been waking up much later (at around 7:30am), which delays