Hi,
Sometimes the text field does not update correctly when typing in Whatsapp. When the cursor goes to the second line, the text field is still only one line high, which means that I can't see all the typed text. Swiftkey and Whatsapp are updated, and this has happened with iOS 10 and 11.
I don't know, if the root cause is in Swiftkey or Whatsapp, but I will report this also to the Whatsapp support.
Thanks!