There's been an iOS 11 bug affecting a lot of people lately that causes "i" to autocorrect to A[?]. Thankfully, Apple today released an update to address the problem.
iOS 11.1.1 is now available to the iPhone and iPad. Included is a fix for the aforementioned autocorrect bug as well as a bug that'd cause the "Hey Siri" hotword to stop working.
This update is a small one, weighing in at just 54MB on my iPhone X. If you're running an iOS 11 device, you can snag this update by going into Settings > General > Software Update.
The autocorrect bug was a frustrating one, especially because it affected users whenever they'd try to type "i", which is a pretty common thing to say. It took Apple a few days to get a fix out, but at least it's finally here.