Unoxidized copper blocks in the trial chamber's "grand_staircase_3" structure aren't waxed

The unoxidized copper blocks in the trial chamber's "grand_staircase_3" structure aren't waxed.

Steps to Reproduce

1. Create a new world, preferably a flat world.
2. Get a structure block, set it to load mode.
3. Put the minecraft:trial_chambers/corridor/atrium/grand_staircase_3 in the structure name
4. Load the structure.
5. Check the unoxidized copper blocks.

Observed Result
The copper blocks aren't waxed, causing them to get oxidized over time.

Expected Result
The copper blocks should be waxed.