Mark Rabideau - http://many-roads.com
"For every complex problem there is an answer that is clear, simple, and wrong." H. L. Mencken
dwm ~Reg. Linux User #449130
20 Jan 2021 ~ "End of an Error"
Use arandr to set all monitors (resolution, position, select primary, etc.). Set as Primary the monitor you want the panel to be. Apply the changes. Save the layout using arandr and you will have a small bash script to re-do all your changes automatically.
If the panel didn’t set up properly yet, use arandr to move a monitor a bit, apply, and then move the monitor back to its position.
This is the easiest way. You can also use the terminal to do this.