Track embed (iFrame) erratic beahviour

[andydog66]

Hi

I've created a site for a songwriter that contains a number of iFrames using the track embed code. https://patrickmascall.com/discography/

For the most part this works but sometimes when clicking on the play button on an iPhone, the message "Open in Spotify" appears with the 'Cancel' 'Open' options showing.
I can't work out why it works on some iOS devices and not others.
All are using the latest iOS.

Thanks

(iPhone 7, iPad)

Operating System

(iOS 10)

My Question or Issue