7.5 month old - Falls asleep fine but then wakes up all night?

Daphne.
Here's your newest sleep regression post haha! But mines a little funky ... LO goes down for bed super easy. We do lotion, PJs, nurse and shes usually 80% asleep or pretty out of it by the time I lay her down and I can walk away no problem. BUT cue her next wake ups which have been every 2-3 hours all the sudden and she's crying awake! I finally had her CIO last night .. it was like one fussy cry for 5 minutes the every 5 minutes she'd kind of shout out and finally went to sleep. Question is - why does she go down so easily but wake up so much and not go to bed on her own?? I just keep nursing her half the time except for that one at 3 am when I just gave up. Is she really that hungry or do I need to night wean and stop going in and feeding her - she eats fast so each time she definitely has eaten not just comfort sucked.
She eats oatmeal 2 times a day at daycare, 3-4 6 oz bottles then nurse when we get home at 5... puréed food, and nursed before bed. Do I need to supplement or something?