Having an issue with listening to my EX2 through the App

Good morning.
I have some audiobooks on my EX2 NAS which can be long/large files.
When I listen to them through the My Cloud App, it will play the first 5-17 seconds of the file, then quit, and start over from the beginning.
Yet, when I listen to them through my OPPO player, it does not have any issues. So it has to be the app…

What can I do to correct this?

Thank you.