When I copy from tmux, selections are appended to the system clipboard rather than replacing its existing content. I see this behavior both with mouse drag and release, and using the keyboard to copy selections. I would like to change the behavior so that copying from tmux works the same as copying elsewhere, i.e. it replaces the content in the system clipboard with the content copied from tmux.
This is with tmux3.0a on 5.4.13-arch1-1 GNU/Linux. I tested with a clean
.tmux.conf only containing
set -g mouse on in both kitty and gnome-terminal.