Uploading video using iframe in IOS application Ionic V3

I am using Iframe to upload video in ionic 3 ios app. In Iframe I am showing the PHP server page in order to upload video in chunk mode on vimeo as a client . But the uploading speed in IOS app is very slow as compared to android app. I am not able to find out why It is taking that much time in IOS app. For Example one video with 30 mb taking few seconds in android app but same video in IOS application is taking 2-3 minutes or more. Time increase more as we increase the video size, but the main issue is it is taking triple time as compared to android.

Please suggest any solution or guidance so i can resolve this issue.