What is the reason that you needed to burn the bootloader?
Reason for asking is that are two parts involved in uploading via USB. The 328P and the serial-to-usb converter. If the 328P is OK (sounds like it) the serial-to-usb converter might be faulty.
How is your Uno identified by the operating system? As "Arduino Uno" or as something else? If it's not identified as a CH340, you can run the loopback test (Loop-Back Test Instructions).
Which operating system?