Why does the display only show 1 phase “Input” if the input has 3 phases +N + ground? (mode 5W 3P+N+PE)

[Tecnofull]

The control unit is labeled as SRT10KLI. Interestingly, another similar piece of equipment next to it with the exact same configurations is correctly displaying all three phases.

Does anyone have any idea what might be causing this display issue?

We also have an input Bypass switch, a SBP16KRMI4U, whose rated input voltage is: 230/400V 50/60hz, 3P+N+PE.

Thanks a lot.