Epplus - Reading through filestream. The process cannot access the file because it is being used by another process. - - epplus

Question

I’m having an issue using EPPlus 6.0.6 on the server within an IIS process. I upload an xlsx to the IIS server, then call the method to process the file (read from the file only.) When finished, I want to remove the file from the server folder, but get the error:
The process cannot access the file because it is being used by another process.
Calling method:
Processor processor = new Processor (filename)
{
Await processor.Process();
try { File.Delete(selectedFile); txtStatusMsg += “Cleanup Succeeded”;}
catch (Exception e){ txtStatusMsg += $#"Cleanup Failed - {e.Message}"; }
// error occurs
// ex.message is
// The process cannot access the file because it is being used by another process.
}
The Process method has:
using (FileStream fs =
new FileStream(filename ,
FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
using (ExcelPackage srcPkg = new ExcelPackage(fs))
{
// read from the file
foreach (ExcelWorksheet srcWs in srcPkg.Workbook.Worksheets) ...
}
}
The file is still locked; I would expect the srcPkg to be disposed after the using block, and fs to be closed/disposed after its using block.
I’ve tried
srcPkg.Dispose();
after the for loop, and
fs.Close();
After the srcPkg using but neither help. Restarting IIS releases the file.
Can i force the file to be unlocked in some way?