Can't close auto-opened Excel windows

When I export XLSX reports through a business tool, it automatically opens a copy of the report once it is downloaded. I haven’t been able to find a way to stop this behavior, so I end up opening up a second instance of the reports with the Use Excel File activity and then end up with these extra windows open and taking up valuable memory. I’m having trouble getting StudioX to recognize the windows that were automatically opened and then close them and the new Modern interface is also having trouble with the Close All Windows submenu in the taskbar. Any ideas on how I can close those extra windows? Thanks!