Keyboard Lag in Journal App (17.4.1)

I have a lengthy entry in my journal and when I add more text to it the iPhone keyboard lags a lot. It takes like a half second to register a click and sometimes longer. Have had similar issues when making a long Reddit post too.

seems to be whenever there is a large wall of text, adding more text lags the keyboard. As soon as I exit that app and go onto Google or WhatsApp and start typing, it returns to normal.