Convert Google Drive M4V video with glitch to MOV video keeping the audio

I have a 63-minute M4V video that plays well in Google Drive (including audio), but when I download it to my Mac the video works but there is no audio at all with the video (seems to be a technical glitch). There is no audio in QuickTime, iTunes or iMovie when I play the video on those platforms. The audio does work when I play the video in VLC, but that isn't of any use to me because I need to edit the video in iMovie. (I've tried all the tips out there on trying to use VLC convert it to a MOV file or an MP4 where audio works, but none of these tips work, the audio is still absent.) So, please convert this Google Drive M4V file into a MOV file which keeps the audio, thank you