tmux-continuum/docs/multiple_tmux_servers.md

Behavior when running multiple tmux servers

(This is safe to skip if you're always running a single tmux server.)

If you're an advanced tmux user, you might be running multiple tmux servers at the same time. Maybe you start the first tmux server with $ tmux and then later another one with e.g. $ tmux -S/tmp/foo.

You probably don't want to "auto restore" the same environment in the second tmux that uses /tmp/foo socket. You also probably don't want two tmux environments both having "auto save" feature on (think about overwrites).

This plugin handles multi-server scenario by giving precedence to the tmux server that was first started.

In the above example, the server started with $ tmux will do "auto restore" (if enabled) and will start "auto saving". "Auto restore" or "auto saving" will not happen for the second server that was started later with the $ tmux -S/tmp/foo command. The plugin will detect the presence of another server ($ tmux) and give it precedence.