Adding an audio to a collection

Hiii everyone. I just got a problem on audio . com. I tried to upload my audio to a collection but it doesn’t work even thought I tried few times with different collection type such as audiobook and it works for the second episod ( which is 17min), folder and album. My episod ( it is a podcast) is 27min long maybe it is too long. If somebody knows the answer it would be awesome.

Thanksssss

Anouck