I have the exact same issue. It started about 4 weeks ago, before that typing was very quick. No other programs have this lag, therefore it's clearly an Evernote App problem. I'm writing the notes for my latest book in Evernote, and my latest (chapter) Note is only at 4,000 words, and had no problem typing the previous (chapter) notes that were 10,000+ words per Note 5 weeks ago. I'm giving it another week and then I'm moving my writing Notes for my book to Android Word.