This has been a long running issue with Spotify on iOS. When in Airplane Mode, anytime the user goes into the app to do anything, they have to click through a pop up asking you to "Turn Off Airplane Mode or Use Wi-Fi to Access Data". We know this, we INTENTIONALLY turned on airplane mode because we're on an airplane. This has been requested here
but for some reason we can't get this thing fixed. All of those ideas have been closed because they didn't reach 50 votes, but combined they are well over 50. Let's just call that enough, and please get rid of this pop up.