6 month old still wakes 3 times at night?

my son will be 6 months next week and is still waking 3 times at night like he is starving. he is on formula and eating food . food isnt the issue we even stopped feeding him to see. he wakes up tossing and turning and the take a bottle like he hasnt eaten . he is my 3rd and I never had this issue with the others. I have got to get some sleep . at 2 months he was sleeping through the night that lasted about 3 weeks. any tips