S24 Ultra speaker sounds become muffled if volume is decreased during calls

[Members_r0jpNRM]

S24u speaker sound during call is clear  just at maximum volume level, but as decreased just two step the sound becomes muffled, and this happens just during phone call, not music or video. This problem seems to happen after latest update.

[Members_r0jpNRM]

Any similar problem? 

Any help?!