Windows Server versions all tested to server 2022
If windows Server is reporting incorrect disk space consumed/available one place to look will be your search index most of the time I have found they are overly bloated, last one was 82 gig.
The location to find the file is C:\ProgramData\Microsoft\Search\Data\Applications\Windows and look at the size of Windows.edb if it is overly large issue a Delete and rebuild. Go into your control panel and then into the Indexing Options and the advance tab where you will find a rebuild command.