Plasma 5 activities disappearing when cloning output to external monitor (projector)

I use the following command to clone the output of my laptop’s screen to a projector (via HDMI/DP) at work:

xrandr --output LVDS1 --auto --output HDMI1 --mode 1366x768 --same-as LVDS1

(Note, I have disabled the KScreen 2 service, because it is more convenient for my to just use xrandr)

However, I have a problem with how Plasma 5 reacts to it. I only use a single activity, and normally my desktop looks like this:

However, when I run the xrandr command, my desktop changes to this:

And the weird thing is that if I right-click on my desktop and select Activities (Which then brings up the Activity Selector showing only my one Activity), then my desktop changes back to normal, and stays that way until next time I plug the HDMI/DP cable in, and run xrandr.

Is there a way that I can tell Plasma to just leave the activities be, and be the same in all situations?