Sensitivity constant change; constant background

Hello! I cannot figure out key terms to search for this issue and Sleep as Android has served me well (paid member! very informative app).

Despite a constant background noise, the sensitivity of noise (i.e., the threshold for detection) keeps changing. Sometimes it requires high sensitivity and other times low sensitivity – this can change within the same session/night/minutes, meaning I find it is too sensitive, next I find it not sensitive enough, etc.

I also find that if I make a loud noise at the beginning, the detection changes, but then this messes with the regular sensitivity noise detection.

Any optimal hints to deal with this? Maybe I am missing an option to ‘stabilize’ this.

Thank you! xo