The default virtual keyboard on my iPad Pro has stared doing clever conversions including converting ascii single quotes into 6-9 curly quotes and even turning two hyphens into a long dash. The two are a disaster when writing code or markup. I don’t think this happened in ios11? Not sure about other iPad models ?
It’s also a disaster for languages such as Scottish Gaelic where initial single quote is often used as a marker for an omitted letter at the start of a word, so it needs to be a 9 quote as it is not a part of a matched pair. Example: ’S e for Is e but the I is almost never pronounced and the two words are then joined into one spoken word. That drives writers mad in word processors.