Reply To: How do I make mesh lights (emission shader) work in EEVEE?
Commands back! There was a white point light hidden from preview but not from rendering. Due to the fact that the camera icon for enabling/disabling the rendering of an object isn’t visible in the “Outliner” per default, I forgot to disable the point light. Now it works as expected:
But parts of the white light before nevertheless originated from the light that the (default material) grey plane reflected in its original orientation.