GL8200 AT response

I have a recently purchased GL8200, connected to a windows PC via serial port. When connecting via Putty and entering AT, all I get back is ▒ (in case that doesn’t show up here, it’s a block symbol). Does anyone know what that means / where I might have gone wrong?

Usually, getting garbage displayed by a terminal indicates that you have the baud rate wrong.

Yep… Made the mistake of sticking blindly to the user guide’s recommendation of 115200… 38400 worked. Thanks!