modified by column

hello everyone , My Main question is what triggers the Modified By column. Recently i had an issue in my SPO site , Employee A has a folder with 10 files in it and the Modified By Columns shows Employee A for all files ... now suddenly all files are showing that they are modified by Employee B ... what changes the modified by ? could it be Sync ? or what else ? Note : (Employee B has access to Employee A files)
3 Replies
There are some default columns which SharePoint maintains internally, few of the columns are Created, Created By, Modified, Modified By. These columns are automatically updated by SharePoint whenever there is a change in the metadata information of a list item or file and it is saved. Once it is saved, a few columns with the above mentioned will automatically get updated.
can you please give example of a change in the metadata ? as my Employee B is claiming that he just performed a Sync to OneDrive for Business
best response confirmed by robert_robert (Contributor)
I think Onedrive sync will update the Modified By field. If there is any change in filename or content of the file, it will update the inbuilt SharePoint columns. Syncing to Onedrive is something like checkout and check-in the files to his/her drive.

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