5 minute nursing sessions during the day - 30 minutes overnight

Over the last few days my 12week old has started being fussier about eating during the day and his daily nursing sessions have gradually gotten shorter. He was nursing for ~20 minutes every 1.5 to 2hours during the day and waking 1-2 times overnight to feed for about ~10mins. Now he’s nursing ~5 minutes every .5-2hours and waking 2-3 times a night to nurse for ~25 minutes 😫

During his daytime feeds today he was showing more signs of reflux and grassiness which I think is why he wasn’t nursing as long, but then he’d act perfectly content sometimes for 2 hours after a five minute feeding. He never acted starving in between. Almost more disinterested in feeding. But then overnight he acts ravenous. He doesn’t show any reflux signs overnight. Have we somehow gotten our schedules switched?