Imac not syncing to Icloud

I was trying to add another device to my icloud storage plan, in doing so I logged out of my apple id on my mac and into my partners as the 2TB was set up on her device. When I logged back in on my apple id, initially it appeared as all my desktop files had dissapeared. Over time they started to reappear. However, now when I access a file and make amendments, it dopes not seem top sync upto icloud to make available on other deices. I just get the cloud beside the file and when I hover over it it says uploading but never seems to finish.

What am I doing wrong?