App Center: In-app updates disabled: This release was either side-loaded or downloaded using a browser in private mode

Question

When using fastlane to generate an Enterprise ipa with the following fastlane code

platform :ios do
  desc "Create ipa for Enterprise distribution"
  lane :generate_ipa do
    gym scheme: 'SchemeName',
        configuration: 'Release',
        export_method: 'enterprise',
        clean: true,
        output_directory: "./fastlane/builds"
  end
end

It will work and an ipa will be generated. However the very first time I open the app, I get the warning In-app updates disabled: This release was either side-loaded or downloaded using a browser in private mode.

Any help is greatly appreciated!