The bottles are leaking. I switched the nipple to a size Small, but the flow is still too strong, and the baby is choking.
The anti-colic system is supposed to work flawlessly, but it doesn’t. Air remains trapped in the nipple and cannot be released—there's always a bubble. Even when pressing the air out through the pouch, air still stays inside the nipple. And if the pouch isn’t full, there’s even more air—and more issues as a result.