My daughter was the same way. Huggies and Luvs made her skin really red and irritated. Pampers was the only brand that didn’t bother her skin.
I can’t imagine she need to go up in size, She 3 months old and in size 3 already It weird cause we been using up & up brand and she was fine with them till this week
Maybe add more of ointment you use.
I cloth diaper and have great brand recommendations if you want to try that
Sounds like they're irritating her skin. Does it seem like she needs to go up a size? Of not, you could try to exchange any unopened boxes/bags of that brand for another - some stores give credit even without receipts.