Hi LloydPalmer94,
Thank you for reaching out to Microsoft Community.
May I know how did you disable the camera on the Surface Laptop 3? Was it through Device Manager? If yes, please try disabling camera from the UEFI screen of the device. Check this page for the steps on How to get to the UEFI settings. Once you are in the UEFI screen, go to Devices then the disable the IR Camera on that page. After that, just choose Exit > Restart Now.
If still issue persist, try setting the external IR Camera as default through Control Panel. Open Control Panel > Hardware and Sound > Devices and Printers. Your external monitor camera should appear on that page, right-click on it and choose Set as default.
If this answer your question, we highly encourage you to inform our Community by clicking on Yes or marking my post as an answer. This will help other members who may have the same issue as you. Otherwise, don't hesitate to update us so we can further assist you.
Kind Regards,
Marrion Y.