4 month old won’t eat

Just starting with a 4 month old who is a very poor eater. The thing the mom has found to work the best is “dream feeding”, getting baby almost asleep and then feeding; she dreams feeds for around 45 mins and only takes about 1-1.5 ounces mom had to do this about every hour and half. Baby refuses to eat while awake. At first thought nipple aversion, but she takes a paci fine, although she doesn’t really suck on it, so now thinking sucking issues?

Mom has taken baby to all applicable doctors; pediatrician, gi, swallow study etc all with little to no advice any suggestions?

My suggestion was to get baby on 90 minute wake/sleep/window, when falling asleep offer her bottle let her drink as much as you can get her to but when she falls asleep let her sleep (as opposed to waking to try to get more intake). And repeat cycle throughout the day. Reevaluate in a couple days to see if this is helping or changes need to be made.

Baby is normal weight (around 10th percentile and hitting all milestones)