This article details the difference between “Save as” and copying the report file.
If you want to copy a Solver report to reuse it, you will have to use “Save as” in Excel. This is because the report has its ID linked to it. When using the “Save as” function the report will get a new ID.
If you copy the file and rename it in File Explorer, then the ID will remain the same. You will then have two different reports, but Solver will only see one because the ID is the same