I may be wrong, but I'm pretty sure this is indeed a bug when you have more than 2 monitors with Budgie. When I used Budgie (Now on Plasma) I had to do this:
Note you will have to modify this command specific for your usage. Copy and paste will not work.
xrandr --output DP-1 --mode 1920x1080 --output HDMI-1 --mode 1920x1080 --same-as DP-1
This is not persistent, your modified version of this command will need to be run after every boot, so you may want to make a autostart for it.
If you run xrandr
, you can identify which monitor is which to ensure you mirror the correct one.
I have not used Budgie on a multi-monitor system for several years now. So there may be a fix / easier work around.
So imagine this monitor setup based on xrandr port identifiers:
TV Monitor 1 Monitor 2
[ HDMI-1 ] [ DP-1 ] [ DP-2 ]
In the original command I'm mirroring DP-1 (Monitor 1) to HDMI-1 (TV left)