YouTube can't access camera

My church recently got a Precision 7550 for use with new sanctuary technology. However, when we try to "go live" on YouTube, we get the message that the camera can't be accessed because it is already in use by another app, even when no other apps are running. We have tried disabling firewalls, choosing the right camera within YouTube, and adjusting the privacy settings for the camera but nothing has worked. We had to go with "plan B" and use my personal laptop to live-stream last Sunday, which is not sustainable. Any ideas on how to fix the issue?