So I took a huge risk and fixed my MB21P. At least it works now! It wasn't working before
DO AT YOUR OWN RISK DO NOT BLAME ME IF IT MAKES IT WORSE OR BREAKS YOUR PC I TAKE NO RESPONSIBILITY.
Unplugged any USB dongles you have may. Just plug in mouse, keyboard and broken dongle.
I downloaded the firmware from:
https://www.tempotec.net/pages/firmware-download for the Sonata BHD/E44/E35 as they used the CS43131 chipset (albeit dual)
Use USBDeview (
http://www.nirsoft.net/utils/usb_devices_view.html) to determine what is the vendor (VID) and product ID (PID) of the broken dongle (it will say Firmware Update Bravo HD)
Open the firmware flasher from Tempotec, where is says VID and PID, copy over the the 4 digit codes of each and just attempt to force flash it. It will spit out an error once it finishes trying to flash. Once it finishes, unplug your MB21P and plug it back in. It now should be detected as a sonata dongle and worked for me somehow.
edit: if this firmware doesn't work for you, you can try the HD II and HD III firmwares from tempotec china's website.
DO AT YOUR OWN RISK