The message
from "Vortex" contains these words:

Can anybody explain the above statement in more detail, please?

The thermostat is in the fridge compartment. If the exterior temperature
is so low that the fridge bit doesn't feel the need to come on the
freezer won't get cooled either.

This is because the freezer doesn't have its own thermostat.

Some fridge freezers do. Your doesn't.

--
Skipweasel
Pay no attention to that man behind the curtain.