Hi there deary. I hope that this find you well love. You see there is a huge possibility that the rashes are from the napkins. This happens to every child. It happened to my son too. I remember that I changed them once because I thought that the ones I had been using werent good enough. I was wrong just after I started using new napkins he started having rashes! So I doubt there is anything else happening to your baby. There is something else like a allergy to something else… Chronologically speaking that doesn’t seem to be the case. You said that the rashes showed up when you started using the other napkins. It is definitely the napkins. Hope you found this helpful.Take good care of yourself and your angel… God bless you dear!