While you don’t need to know this to solve the problem, knowing it may be useful at some point in terms of how configurations can be set to work.
I hadn’t thought about you having a Thunderbird configuration.  I thought you meant that when you opened the volume control, your volume went down and stayed down even when you returned to Thunderbird.  Since you had a Thunderbird configuration, the volume evidently got higher when you returned to Thunderbird.  It wouldn’t have mattered what you did, any time you left the Thunderbird window, the volume would have gone down and every time you returned, it would have gone up.  The cconfiguration was set to be active any time you were in the Thunderbird window.
Configurations can be set to be active when you are in a program window and not active when you aren’t.
Gene
-----Original Message-----
*From:* Howard Traxler <mailto:htraxler7@gmail.com>
*Sent:* Saturday, November 20, 2021 2:37 PM
*To:* nvda@nvda.groups.io <mailto:nvda@nvda.groups.io>
*Subject:* Re: [nvda] Volume in Thunderbird
Thank you Brian and Gene.  I will file those suggestions.  In the
meantime, I deleted the thunderbird configuration from NVDA.  I didn't
know it was there nor what it was good for.  So now everything is better
(I think).

Howard

On 11/20/2021 2:24 PM, Gene wrote:

Evidently, you are saying that it goes down when you do nothing but
open the volume control dialog.
I don’t know why it is happening but the easiest and fastest
workaround would probably be to create a shortcut and a shortcut
command to open the volume control.  You could use a command like
control alt v and you can do it from anywhere so inside of
Thunderbird, you can execute the command, then, when the volume
control dialog opens and the volume goes down, you can simply close it
and I believe you will be placed back in Thunderbird without having to
move to it.
Gene
-----Original Message-----
*From:* Howard Traxler <mailto:htraxler7@gmail.com>
*Sent:* Saturday, November 20, 2021 9:11 AM
*To:* NVDA <mailto:nvda@nvda.groups.io>
*Subject:* [nvda] Volume in Thunderbird
When I open thunderbird, the volume jumps up to be uncomfortably loud.
Can't seem to keep it from changing.  When I go to the system volume
control, it goes back down.

HELP?

Howard