Hi Alaka'i Hennings,
Thank you for coming back and sharing the outcome.
I'm glad to hear you were able to identify the cause of the issue and get your JBL TUNE510BT headphones working again. It sounds like setting the headphones as the default audio output device resolved the problem, even after the driver updates and factory reset.
I also appreciate you taking the time to post the solution. It may help other users who experience similar symptoms where Windows detects audio activity, but no sound is heard through their Bluetooth headphones.
If you run into any other questions or need further assistance in the future, please don't hesitate to reach out in comment section. I'd be happy to help.
Have a great day!