Synapse 4 broke my Blackwidow v3

My BlackWidow V3 started typing infinite loops of characters (example: ž/ž++ž8+/đ/) immediately after updating to Synapse 4. The issue persists on different computers without any Razer software installed. I tried the official Firmware Updater, but it says the firmware is already up to date and won't let me re-flash. I also tried the ESC+Caps+Space hard reset, but the keyboard continues to type on its own. This is a firmware corruption caused by Synapse 4.