Help: Speakers mutes below certain threshold volume

I have a budget bluetooth speaker which has an AUX input too.

Problem is it kills the audio when volume goes below a certain threshold in the linein/AUX mode.
This means that when I’m watching a movie or video, if there’s just background noise and no loud noise in the scene it kills the audio, until there’s a voice or louder audio, in which case it restores everything.

It’s not a problem with the AUX cable itself or the sound input i.e phone/PC/DAC.

If the problem is something to do with dynamic range then how do I fix it?