Nappy HELP!

My son will be 7 weeks on Monday and was weighed a week ago at 5.8kg and 58cm so he’s a little chubba.

By week 2 he was already out of newborn nappies and moved him on to infant which should realistically be up to 8kg (I know this is just a guide).

Now it seems that he’s already too big for the infant nappies as they leave marks/imprints around his thighs and become very very uncomfortable for him if he has a long nap and they become full even leaving marks on his bum. We’ve tried loosening the waist which affects the tightness around the thighs but leaves it way too loose around the waist.

Anyone else had this problem? Has anyone found if different brands made a difference? Surely he can’t be ready to move to a crawler nappy at 7 weeks old 😰