Pairing PS4 Controller with PC causes a key to act as if it's held down

Hi, I'm trying to connect my Dualshock 4 to my PC using a mini Bluetooth USB adapter. I can connect it but as soon as I open a game it appears that left trigger is being constantly activated despite it not showing up in DS4 or in-game inputs but it means the game is unplayable. This happens with or without DS4Windows open so much be an issue with the Bluetooth

Any ideas on how to fix?