M190 command inconsistent with Marlin?

[BillMerryman]

I am trying to print without bed heat, so just set the bed heat to 20 degrees. This produces M190 S20 in the gcode. According to https://marlinfw.org/docs/gcode/M190.html this should only block if it has to heat the bed. In my case it looks like it is permanently blocking because the bed never drops to that temperature.