Is Gather switching your audio inputs every time you switch tabs? Or are you able to hear others but they can't hear you? Huge changes in audio quality when you mute and unmute? This page may provide some clarity.
Every Bluetooth accessory comes with a built-in profile, which is a package of software that tells the device how to "treat" the accessory. Some devices will automatically sense a bluetooth accessory, and then apply an incorrect profile to them from their own library. This page provides some examples and what you can do to make your accessories work better.
If you find that you can only hear others but they can't hear you, this is may be the issue you are encountering:
Bluetooth A2DP, a type of Bluetooth profile, does not allow for stereo audio plus microphone at the same time.
Many Bluetooth headsets, widely produced before 2018, use Bluetooth A2DP. Some mobile devices will accommodate the limitation of A2DP by switching between sending microphone inputs and receiving stereo audio input quickly and automatically. Some devices (computers, tablets, etc.) do not support the automatic switching of inputs and outputs required by A2DP for a smooth experience.
One solution would be to use a separate microphone if you wish to use Bluetooth headphones.
The following instructions dive right in to managing your audio settings. (Read the Video and Audio Settings Introduction if you need a refresher on how to access these features.) You can manage your audio settings before (Gif 1) or after (Gif 2) you're logged into Gather.
When you select your input (mic) in Gather, your computer will generate a list of what it views as available. In the gifs below, the drop-down menus show several options for the same headset. Each option is a different profile that can apply to the device.
Warning: Firefox for Windows and Mac does not allow the user to set a separate output.
Finding the right combination that works for you may take some trial and error.