Excel does not release old file on network when saved with a new name

A file on a network drive is opened and then saved with a new name (or saved in another folder with the same name).

Ex: Open Test1, Save as Test2, go to Explorer and delete Test1.

Explorer says file is in use in Excel.

When Excel is closed the file can be deleted.

Above is what happens with the files on a shared network.

If done on C drive it works as expected, the file is deleted.

It has been used for years with VBA (Save As and Kill) and this issue began this summer, probably June.

The VBA error is 'Permission denied'.

Any suggestions on how to make Excel release the file not in use?

Same problem with Word, so perhaps an Office issue.

Regards Ejgil