If you’re using only one monitor, simply duplicate and scale your laptop screen instead of using the extended approach.
To give you a rough idea, this will look to something like this: xrandr --output eDP1 --mode 1366x768 --scale 1x1 --output HDMI1 --same-as eDP1 --mode 1920x1080 --scale 0.711x0.711
Use xrandr to find the monitors names and resolution. The scale option is simply the ratio between your 2 resolutions.