3.5m suddenly extra cranky and hangry

My 3.5months old baby boy recently has been extra cranky/fussy & hungry. And would cry for no obvious reasons. Not feed time, tummy not bloated or hard, not sleepy. Initially he’s drinking 120ml/3hrs but it started to not be enough for him as he would cry after milk finish and the interval would not last 3hrs. Usually arnd 2.5hr. Which we then increased to 150ml and he did not cry afterwards. But would still sometimes cry murder by 2.5hr and hungry again. Sometimes can last 3hrs sometimes 2.5hr alr cry murder and no choice we had to feed him. When he cry murder nothing works, white noise pacifier rocking him talking to him swaddling etc. He’s on full formula. I checked, he did not gain height, weight only gained like 100g. Is this growth spurt or just a cranky phase ? And also, he just learnt how to flip body.