When scrolling my tmux automatically scroll down

Question

I am using tmux (I connect to linux with exceed over ssh) I added the magical set -g terminal-overrides 'xterm*:smcup@:rmcup@' which enable mouse scrolling and that works very nicely !

Though I have a problem, when I scroll up with the middle button for some reason the cursor get soon back down the page (like if I was entering q). I don't know if it is a refresh thing or...

I add my .tmux.conf file in any case

# change prefix key to C-a like screen and also C-a-a to send it into
# a session within a session
unbind C-b
set -g prefix C-a
bind-key a send-prefix
# toggle last like screen
bind-key C-a last-window
bind-key C-c new-window
# a readable status line
set -g status-bg blue
set -g status-right "%Y-%m-%d %H:%M:%S"
set -g status-interval 1
# misc tweaks
#set -g display-time 3000
set -g history-limit 5000
#set -g bell-action any
#set -g visual-activity on
#set -g visual-bell on
# Sane scrolling
set -g terminal-overrides 'xterm*:smcup@:rmcup@'
# Bellow allow scrolling with mouse (enter normal browsing mode automatically)
#set -g mode-mouse on

Answer 1

set -g status-right "%Y-%m-%d %H:%M:%S"

This config makes tmux update status line every seconds.