When I try to use the text editor in the playground on my phone (Pixel 4/chrome) it either doesn’t let me type at all, or let’s my type for a while before breaking. When this happens I can see that the editor thinks I’m in a different place than my keyboard does. Typing when it’s in this state does not produce changes on either line though.
In this screenshot you can see that the editor is confused about where I am, with a cursor on both line 70 and 74: