Microsoft says that certain Bluetooth devices might start experiencing pairing and connectivity issues after Windows users apply cumulative, security, or monthly rollup updates released today.
As detailed by the Windows support document published today by Microsoft, "These security updates address a security vulnerability by intentionally preventing connections from Windows to unsecure Bluetooth devices. Any device using well-known keys to encrypt connections may be affected, including certain security fobs."
BLE Titan Security Keys and Feitian Multipass blocked
The security fobs part at the end refers to Google's Bluetooth Low Energy (BLE) Titan Security Keys with a T1 or T2 code which were recalled last month and to the Feitian Multipass (Feitian CTAP1/U2F Security Key).