I’ve tried multiple times to transition off formula to whole milk, semi skimmed milk and even oat milk. Every time he gets skin rashes and really bad nappy rash, so I’ve had to transition back to formula because I can’t put him through it. He’s fine with yoghurts and a little of milk in cereal but as soon as you go to 4oz or more I run into problems, and I’ve done this gradual over weeks it’s not just big bang. Anyone experienced similar? What was it? How did you transition off formula?