First row missing when using a monitor

Dear all,

when using a monitor in combination with a Power9 system (raptor black bird),
the top line is not displayed. I verified this when using top or vi.
However, there is enough space on the monitor display let at the bottom to
show one additional line below the lowest displayed one.

So it seems that the number of rows is correct, but when displaying them,
they are off by one resulting in the first one not being visible.

This happens with the main branch.

Any idea what could be wrong?

Best regards
Michael