Maybe this issue is releated to Privacy settings on your MacBook.
Please choose Apple menu > System Preferences > Security & Privacy > Privacy tab > Full Disk Access, check if Office applications ( Word, Excel, PowerPoint and etc) have enough permissions to access the drive and files, you may tick the box of these apps, to add an app, click the Add button, select the app in the list, then click Open.
Please also refer to "Change permissions for files, folders, or disks on Mac", make sure you have read & write permission for these files. (Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.)
Besides, I suggest you try to move one file to other location to check this issue.
Any updtes, you may post back.
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