Status Indicator flashes quickly

Pairing mode active — the controller has entered pairing/discovery state.

? What Causes This

User initiated pairing by pressing and holding the pairing button for three seconds.

Ensure the controller's back gear is in the correct position for your desired connection type.
Pair the receiver (unplug and replug USB) or unpair/repair via Bluetooth settings.
The indicator will become solid when connection is successful.

Source: page 8 of the official manual

From the manual

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