Question: Drawing in iBooks
So, I opened a Word document I had sent myself in iBooks on my iPhone, converting it into a PDF. Sometimes, the top bar offers the option to draw on the document, and I've tried it - it works well - but then the option arbitrarily disappears and then sometimes reappears again, only to be gone again the next day? What is the issue here and how can it be fixed?
iPhone 6s, iOS 10.1