We recently released an iOS update, 11.1.1, that contains a fix for autocorrect issues. Let’s be sure to back up your device prior to updating. Follow the steps here: https://t.co/80YRnjDFDk
— Apple Support (@AppleSupport) November 11, 2017
iOS 11 which came in September with the introduction of the iPhone 8 and 8 Plus saw thousands of tweets regarding the same bug.
The iOS 11.1.1 update can be downloaded on Apple products by going to ‘settings’ section. Then you have to click on the ‘general’ and then on ‘software update’.