iPhone 12 mini speaker volume drops in apps

iPhone 12 mini speaker sound/volume issues across multiple apps (volume level drops significantly although the volume level bar / indicator remains at desired level) -

Regularly when listening to music on my iPhone 12-Mini the volume level will reduce dramatically even though the level bar was not adjusted and still appears to be at the desired level. I think it usually occurred when I am physically handling the phone (i.e. looking at the song playing, choosing a playlist, selecting a channel) but I have not found any setting adjustments the help. I have noticed then issue using Apple Music, Sirrius/XM app, and Spotify app primarily while outside during walks. My daughter (with the same model of phone) has also noticed the problem with music and during FaceTime calls.

I have checked all sound related / associated and every other recommended setting (Attention Aware, Haptic, Ringer Volume with buttons, Volume Lock, etc).

Any help or suggestion is greatly appreciated.

Thanks,

Bry