On mobile, you cannot enter newlines on the follow up message input box (the bottom input basically) as hitting enter while typing will submit whatever text is there already. This behavior makes more sense on the top input as it doesn't look like a free textarea input. This isn't a problem on desktop as Shift+Enter is the way to do it.
I believe this maybe be a regression of sorts as I don't recall this being an issue as of some time ago.
I also tested this on two keyboards to assure it isn't a problem on my keyboard's side (hasn't had an update in months though)
I expect for hitting enter on the keyboard to add a newline, as there doesn't seem to be a way otherwise to do so. Videos attached below:
Current Behavior (as of December 17, 2023):
Expexted Behavior:
