Box Folder Filling Up Disk

Hello. None of what is described here is my problem. I have used Box since 2013. I obtained a new iMac with 500 GB storage; 16GB RAM. When I installed Box it installed all of the files from 2013 to September 2021 onto my hard drive rendering my computer useless for working with large files. The Box folder is using 325.67 GB of my disk space. The worst part is I (nor my university's technicians) can seem to delete or move any files from it or figure a workaround. During the move/delete process it appears to remove/delete when I log in again the files return. What is even more problematic is when others upload to the shared folders, I have been getting a message saying something to the effect of cannot sync, download in process. Now with the latest operating system updated this morning, I received this message: "Disk clean up complete! Good news! All of your Box Sync content was saved to Box and cleaned up. This restored Zero KB of your disk space. All of your content is available in your new Box Folder. This is a brand new computer bought by the university specifically for me to complete a project that contains large files. I am the project director. HELP!!!