World Partition Huge Maps and Cook times - World Partition on 5.1.1

Hi Everyone!

Looking for help with some issues regarding World Partition, we converted our maps to it, but it caused those maps to become quite havier in size. The cooking fails often, requiring cleaning cooked folders and not using iterative cooking, which takes several hours to cook the game.
Game overall size increased several times due to it. We used Nanite prior to converting the maps and it was working fine. We are using Unreal 5.1.1

Anyone having similar issues that could point us to any solution please?
Any help is greatly appreciated!

Thanks,
Filipe