main site stuck to 3mb upload limit

I am having issues with upload limits, I have pro sites set but my main site seems now to be adopting the free site 3mb limit

How remove my main site and network admin from this limit?

have tried all kinds of settings, tried making it a high level site but don't really want that as there is unlimited space on the server.

am a bit stuck with this one.

thanks

Kind Regards

JT