WhatsApp spelling red underline missing iOS11

In iOS 10, when typing a message in Whats App, all the errors would be underlined in red (with spell check enabled and predictive switched off - as it causes too many embarrassments). In iOS 11, only the last type word in underlined and as soon as the space bar is hit, the red underline disappears. I normally check the spelling after typing the sentence and not during the typing of the word so when i look back before hitting send all looks fine, hit send then realise it is full of spelling errors.

Tried remove and adding keyboards, resetting dictionaries, disabling and renabling all the spellcheck options - but the problem is still there in whatssap.

Note that in email compositions, and iMessages, it works fine. All spelling mistakes are underlined in red. Problem is only in WhatsApp.