Playback audio issues on GSM

Hi Guys.

This is a really strange one and just started recently.

I cannot hear audio play back on GSM files. I have no problem hearing WAV files but GSM files are a different matter entirely. I know there’s no issues with the GSM files because they play perfectly on VLC player.

They use to play perfectly but for some reason not any more, I even updated to the latest audacity version 2.2.1 but made no difference

Im also using Mac OS High Sierra

Any idea what the issue is?