Changes made to the data source location from a mapped network location to a local file path which has the same format as the network location is not saved when setting the data source for an MXD.
Duplicate of BUG-000092590: The issue described in this BUG are another scenario for an underlying issue that also results in the observed failures described in BUG-000092590. We will include these steps as another test case to ensure any fixes we install will satisfy both cases.
解决办法
When replacing the path of the mapped network drive with the local file path. Click on Replace or Replace all before clicking on OK. The changes would be reflected in copy of the MXD. If the directory structure differs between the local drive and the network location, everything works as expected