Many "Jieli BR21" dongles are actually USB sound cards with a Bluetooth receiver function, rather than standard Bluetooth adapters. This means they can receive audio from a phone to play through a speaker, but they cannot connect your PC to other Bluetooth devices like mice or keyboards.
We tested the against the generic Windows driver using a standard BR21 USB dongle paired with Jieli-branded TWS earbuds. jieli br21 driver exclusive