Hi @Anonymous,
Could you please share a screenshot of your flow's configuration?
Do you use the "On approval, move a new OneDrive file to a different folder" built-in template of Microsoft Flow to create your flow?
This built-in template is used to start an approval process when a file is uploaded into your source folder, if the approver approve this request, this file would be moved into another OneDrive folder that you specified.
I have made a test on my side and please take a try with the following workaround. My flow's configuration as below:


Within Folder field of "When a file is created" trigger, specify Source folder in which the new file is uploaded. Within "Assigned to" field of "Start an approval" action, specify the email address of the approver. Within Folder Path field of "Create file" action, specify another OneDrive folder.
The flow works successfully as below:

Best regards,
Kris