Our pediatrician told us at one of my sons appointments it’s common for appetite to heavily decrease around 1.5 because their growth slows so much it nearly stops
I have heard the same that Dana said. Growth slows down and appetite does too
It could be that their mouths are in pain from the teething so maybe try putting some food in a pacifier so they can get the nutrients!
Mine does it too. Not all the time but he does it too so I hope it is normal 🤷♀️