Missing Audio on Desktop/Web

Hi All
I’ve made around 1,000 cards on my mobile device but when I try to study on the web or desktop client, my audio files are missing.
Some of the audio files are copied links from the www.forvo.com and others are recorded audio, recorded directly from my Android device.
I’m not seeing an error message like the audio cannot be played, and I can see the audio file when editing a card, it just doesn’t give me any option to play it when studying.
Thanks for any help.

This could be relevant:

Thanks a lot, but it doesn’t seem to be a sync issue. All image files are present, it’s just the audio that is missing.

Please use Tools>Check Media in the computer version. Some of your files are not .mp3 files, and AnkiWeb only works with .mp3.

Will do, thanks Damien.