Remember size and placement of macOS VM windows (M-series)

I am using Parallels Desktop for Mac 18.0.2, Business Edition.
macOS guest VMs never remember the size of their windows. Every time I start them from a power-off state, the VM screen is too small and there are black bars on the left and right. It would be very nice if Parallels could remember these window sizes. Placement on the screen would be nice, too, but I care a lot less about that.