This is being investigated. Expect an update in this thread shortly.
It appears related to older versions of Safari (Safari 9 on iOS 9.3
Apple iPhone/iPad) - older than the now currently supported version. ( iOS Safari 10 > )
Note : To avoid duplication of feedback responses, and to improve initial response time, I will be logging issues here and referencing forum items in feedback responses more in the future.
Tested on the oldest supported iOS device I have available.
Resign button is confirmed working on iPhone 6 (2015), with iOS/Safari 12. iOS 9 is unfortunately too old to support going forward, so please check that software updates exist for your device.
Devices that appear not to have received software updates beyond iOS9, so will therefore be incompatible :
- The iPad with Retina Display (3rd Gen) and older 9.7-inch iPads
- The iPad Mini (original)
- The iPod Touch 5th-generation and older iPod Touch models
- The iPhone 4S and older iPhone models
ref : https://www.cnet.com/news/ios-10-compatibility-these-are-the-iphones-and-ipads-that-will-and-wont-work-with-ios-10/