Landing elevation resets to 0 when descending

[thierryd]

I noticed on several flights, as I am flying to high altitude airports (e.g. SKBO 8,400 ft or so), that the ECAM reports the correct airport elevation for most of the flight. But then, when I am in the descent phase (not sure exactly when the change happens), the airport elevation value goes back to 0. Accordingly the pressurization does not follow the correct profile.

I do have the Landing Elevation knob on the overhead set to AUTO.

And out of curiosity, talking about the Landing Elevation knob, I was wondering why switching to manual only allows you to select a value by multiple of 1,000 ft whereas the automatic airport elevation value seems to be rounded to multiple of 100 ft.

[thierryd]

I want to add some more information on this topic. It does not matter what the destination airport is, the issue is present on every single flight. Shortly after starting my descent, maybe 700 or 800 ft below my cruising altitude (which I just left), the LDG ELEV indication, although still indicating AUTO, is reset to 0 (zero). This happens despite the fact that the LDG ELEV has been showing AUTO and the correct field altitude for the entire duration of the flight so far. It seems that it coincides with the pressurization controller starting the descent has I can see the down arrow and a 250 ft/mn (and then increasing) indication right when the value is reset to 0. Cabin altitude is typically around 8,000 ft as expected.

What could be causing this?