Sorry, this is very much a PEBKAC issue. This is a excerpt from my tmux config:
<span style="color:#323232;"># Start windows and panes at 1, not 0
</span><span style="color:#323232;">set -g base-index 1
</span><span style="color:#323232;">setw -g pane-base-index 1
</span><span style="color:#323232;">
</span><span style="color:#323232;"># Use Alt-arrow keys without prefix key to switch panes
</span><span style="color:#323232;">bind -n M-Left select-pane -L
</span><span style="color:#323232;">bind -n M-Right select-pane -R
</span><span style="color:#323232;">bind -n M-Up select-pane -U
</span><span style="color:#323232;">bind -n M-Down select-pane -D
</span><span style="color:#323232;">
</span><span style="color:#323232;"># Shift arrow to switch windows
</span><span style="color:#323232;">bind -n S-Left previous-window
</span><span style="color:#323232;">bind -n S-Right next-window
</span><span style="color:#323232;">
</span><span style="color:#323232;"># No delay for escape key press
</span><span style="color:#323232;">set -sg escape-time 0
</span><span style="color:#323232;">
</span><span style="color:#323232;"># Increase scrollback buffer size from 2000 to 50000 lines
</span><span style="color:#323232;">set -g history-limit 50000
</span><span style="color:#323232;">
</span><span style="color:#323232;"># Increase tmux messages display duration from 750ms to 4s
</span><span style="color:#323232;">set -g display-time 4000
</span><span style="color:#323232;">
</span><span style="color:#323232;"># Bind pane creation keys to reuse current directory
</span><span style="color:#323232;">bind % split-window -h -c "#{pane_current_path}"
</span><span style="color:#323232;">bind '"' split-window -v -c "#{pane_current_path}"
</span>
I hope the comments are self explanatory.
Scrolling works with Ctrl+b Page Up/Down. There are other shortcuts, but this is probably the most obvious. q to quit scrolling.
Ctrl+b d to detach from a session. tmux a to attach. As always, many options are available to have many named sessions running simultaneously, but that is for a later time.