Sounds like something on your server, which I'm not wholly familiar with.
I think it's more of Windows Tech forum you're looking for - or consult your IT department, or an IT specialist.
InDesign creates "IDLK" which is an InDesign Lock File which is generated in the same location as the indesign, it's a hidden file.
Once the InDesign file is open, the IDLK temp file is created, this is to prevent additional people opening the file, as only 1 person is permitted to open a document at any one time.
If the IDLK files are not being removed from the server when you close the file, then that would prevent another user from opening the file.