This is exactly the same issue that I am facing.
Almost similar question here as well.
I have tried all the answers published in the related "StackExchange" questions. I also have tried to increase the Rows and Columns count both using PuTTY settings window and
stty. No luck so far. Hence I am creating this question.
Required details for diagnosis :
root@MyUnit:/#echo $PS1 \u@\h:\w\$ root@MyUnit:/#shopt checkwinsize checkwinsize on root@MyUnit:/#stty -a speed 115200 baud; rows 60; columns 150; line = 0;
If this information is of any use : I am using PuTTY to connect a Linux device in serial mode via a FTDI USB-Serial Converter.