The stock standard firmware has issues pairing, doing an update is important to rectify this.
https://gamesir.com/pages/software-detail
There a link to the firmware update below for the Dongle, the controller updates are done through the the Gamesir software. It would be worth checking out their website for more detail information here: https://gamesir.com/pages/tutorial-how-to-update-dongle-firware