1px overlap between monitors when using display scaling

When using display scaling with multiple monitors, there is a small (1px) overlap between the monitors.

To reproduce:

1. Have 2 monitors, set up in side-by-side
2. Go to display settings, and set both to Custom (0.6 for both x/y)
3. Press apply (then keep)
4. Drag them so they're still side-by-side
5. Press apply (then keep) again

If you maximize a window on one monitor, you'll see a thin (1px) strip of it on the other monitor.