Video Streaming App not working on iPad - Apple rejection

We are building a video streaming app for iPhone. The app has been rejected a couple of times by Apple stating a reason that clicking on the play button doesn’t play the video. Apple has been testing on an iPAD whereas the app is targeted towards iPhone. I found the exact same issue listed on stack overflow (video app rejected by apple for not working on iPAD) - However, it doesn’t have a solution.

Has any one built a video streaming app and faced a similar issue? If so, how did you resolve it?
NOTE: The app works perfectly on iPhone devices - we have tested it several times

Why don’t you tell the reviewers that the app doesn’t run on iPad? You can select eligible devices at time of submission.

We did, but apple needs us to to make the app running on iPAD was well, even though its an iOS app. Their reply was as follows:

“To ensure people get the most out of your app, iPhone apps should run on iPad whenever possible.”

And till we don’t resolve the issue with iPAD, they won’t approve the app on iOS either

As a follow-up, it seemed this issue only occurred during a paid flow on an iPad. The dev created a paid license for testing to alleviate the issue.