USB Serial not working in .NET application Windows 10 PRO

Having a strange problem. I have a .Net app which scans barcodes and retrieves products from a cache file. I am using a Zebra DS457 scanner configured for USB com port. This has worked fine on all of the computers I have configured until now. I have a brand new ELO 22" iSeries computer that came without an OS. I installed Windows 10 Pro and all of the latest Windows Updates.
After configuring the DS457 to USB Serial and specifying the com port I installed my custom application. When I scan a product barcode it beeps 4 times indicating no application received the scan.
Trouble shooting so far:
I reset the scanner to factory defaults and scanned into notepad. WORKS
I reset the scanner to serial and scanned into Hyperterminal. Works
I contacted ELO and downloaded their driver back. I installed all of their drivers.
I installed Zebra 123Scan. Everything seems to work as expected.

I feel like something is interfering but I am not sure what it could be.

Thanks

cf