Back Arrow not working correctly in Message when font size is increased

Since upgrading to iOS 11 my back arrow does not work most of the time when in Message. After multiple tests I found out it is due to a change in font size. If I set the font back to standard everything works fine. If I increase the font size slightly then the back arrow acts like it is trying to edit. I have a 7 plus and my wife has a 6 plus and it is doing the same on hers.