No power on boat through shore cable in marina

[vespucci]

I plugged in my 50A marine shore power cable but received no power on my boat. The receptable at the pedestal definitely delivers power and when I test with my DMM, i read 117V between W and G at the end of my shore cable to my boat. There is sitting a device at my boats fuse box which shows a red LED. Another green is NOT lighting up. I could not find out what this means. The device is this one: Voyant à LED CX³ double 110V~ à 400V~ - vert et rouge - 1 module - https://www.legrand.fr/pro/catalogue/31959-double-110400-v/voyant-a-led-cx3-double-110v-a-400v-vert-et-rouge-1-module
Is the device expecting two hot phases to the ground?