This appears to be an issue with MMM-Remote-Control, which has a “MONITOROFF” command that I was using to turn off the display. That command executes tvservice -o, which according to this documentation “destroys any framebuffers/dispmanx layers associated with the display” that are not restored when the display comes back on. On their recommendation, I switched the command to vcgencmd display_power 0and my issues have gone away.