How can I prevent Siri volume to auto adjust on iPhone?

How can a user prevent Siri volume auto adjust on iphone?

iOS 18.1.1 routinely auto adjusts Siri volume when using air pod pros, making the volume painfully loud. Manually adjusting Siri's volume with voice commands or by having Siri tell a story and using the side buttons only affects the volume for a few moments. As soon as the interaction is over, Siri's volume is raised to previous levels or higher. Siri's volume does not match the volume of other media but has no indepdent slider. The criteria used for volume auto adjust appear arbitrary.

[Re-Titled by Moderator]