Copper blocks in the trial chamber being not waxed

I have noticed two particular copper blocks in the trial chamber that started aging, because they are not waxed by default (unlike all other copper blocks in the trial chamber). The sub-structure of the trial chamber that is being affected by that is called – trial_chambers/corridor/atrium/grand_staircase_3. One of the two not oxidized copper blocks at the lower part of both sides of the staircase are the ones that are not waxed by default.