[OPERA] [Scheduling] [A/C Checks] : confirm button unavailable

Browser is Opera
Trying to set up a A & B check on my new plane.
Due to zoom level, the Confirm & Cancel buttons are hidden.
This is a problem only because I can't scroll down.

Works so-so on Firefox (buttons are half cut) but is usable.
Works quite OK on Chrome or Edge
==> on both three, the low bar scrolls a strange way and stays above, the panel, but is not really annoying)

After extensive testing, it seems that the bug is present only in a specific case : when the level of zoom is setting up the white bar down exactly at the level of the buttons. So the panel is not big enough to open a scroll bar, and not small enough for the buttons to be above that white bottom bar that hides them. It seems more linked to my specific opera setup than to Opera specifically, but might strike other users randomly.

The real bug might be that the low bar is above this panel. I'm not sure what is the design intention here.