Data Storage Space Issue for Switch & Realms!

I have cleared my Minecraft cache data and deleted all my speed run worlds (there were only 11 and all very small in size), yet I am unable to save/download a copy of my Realm Survival world from my Realm ,being about 500mb? I am greeted with a message saying "You are almost out of storage space! Minecraft has restricted access to this feature..etc"

My Nintendo Switch has another 15+ GB left on its internal memory so space isn't an issue in that regard as well as I am able to create new worlds without the storage warning coming up.