If iPhone Settings, Display and Brightness is set to Dark then all in game Message text will show as white text on a gray background hence you cannot see what you’re entering. If Light mode is set, text color is black and is clearly visible. ie problem is only in Dark mode.
Thanks for flagging this up. I’ve created a ticket to review this issue.
Looking at your server stats - it looks like you’re using an iPhone 12 and iOS 14.3.0, is that correct?
No, iPhone 11 (iOS 14.3.0)