Downloads disappear

I am able to download episodes of certain recorded shows onto my iPad, that I can watch while I am traveling in the US when I have no Wi-Fi. But for the last few months, 24 hours after I do the download on my iPad, they disappear from the Download list on the app. My iPad has lots of space and I know they are download it because if I connect to Wi-Fi I can see them in the Recorded shows section. I’m not sure why they won’t show up in the Download section of the app? Without Wi-Fi I am not able to find them or watch them on my iPad.