Audio only playing in microphones

This is a problem that has come up recently. No changes done in audacity but there was a Windows update in the last week.
The exported process from Audacity (Tried MP3 & Wav) is error free and the same as I have used for a long time.

The exported file is perfectly audible using microphones. But file is very distorted and almost inaudible over device speakers.

This problem is NOT only in my laptop. I have transferred the exported file to my friends laptop (Via email) and also to my Mobile device (via WhatsApp). The same issue persists on all devices for both Wav & Mp3 files - Inaudible on speakers & perfect on Headphones.

I have already reinstalled LAME. Uninstalled Audicity & reinstalled (2 versions) - Problem persists!

Is it possible that somehow one of you channels is inverted ? If that happened the sound directed to the right channel could cancel out that on the left for some devices.

What’s the work? What’s the job? That can sometimes give us a clue to what’s going on.

Is it a stereo show? Two blue waves?

Open a copy of one of the shows in Audacity. Tracks > Mix > Mix Stereo Down to Mono.

That will make one blue wave, but does the show vanish or become very low volume and distorted?

Koz