Changing my realm to my Nintendo Switch World

I tried replacing my mine craft realm for a world I had on my switch. Every time I try exporting the world to my realm on my switch it keeps saying Error exporting world. and World export failed. Error after error. I now feel like I lost money because of all these errors I cannot play the world I want to play online with my brother. I do not understand why. I have a solid internet connection 120MBS-200MBS.