Troubleshooting inconsistent voice volume and timbre in character animations

Volume

Have you ever noticed that the volume of a voice varies because you’ve masked a character? In one of my projects, this happened to me with Steffan’s voice (Latest/German). The volume varied significantly, even though the percentage settings were the same. I was able to balance it out by adjusting the percentages.

Voice Timbre

Using a different voice, I generated text scene by scene that was spoken by the same avatar/character. Nevertheless, I received feedback from my testers that the voice sounded different in the scenes. I would confirm that. I then experimented and used other voices. Specifically, this happened to me with Alnilam-male (multilingual).

Have you had similar experiences, or was I just unlucky?