putty ssh tmux issue

Prompt

How can I fix SSH Putty session to make tmux work better with mouse & scrollback history? Here is the terminal setting with regular ssh login: $ tset -q xterm-256color After running tmux though the setting is: $ tset -q screen The mouse wheel does not work as expected, as mouse scrollback makes the tmux bottom bar disappear. Only ctrl-b { works to activate the scroll history, with only the arrow keys working. Shift-mousewheel is the same. Ctrl-mousewheel makes the text sizes larger or smaller. Right click does bring up the popup tmux menu though. The following .tmux.conf entries still do not seem to help: set -g default-terminal "screen-256color" # or "tmux-256color" set -g history-limit 200000 set -g mouse on bind -n WheelUpPane if-shell -F "#{pane_in_mode}" \ "send-keys -M" \ "copy-mode -e" What other diagnosis steps are needed to propose and test a fix?