Another issue that could.of happened, is that when you flashed the firmware ,you selected the wrong one, as each flight controller has its own firmware. So I suspect maybe the one you flashed is for another FC that uses a different gyro so that is why it isn’t detecting it on your pc anymore.
I assume it was all working before you flashed it? In my experience Geprc are a decent manufacturer who don’t have many issues, but when they do they do fix it. I can’t recall off the top of my head what FC the sparrow uses, but should tell you in the manual.