Structure blocks' structure preview doesn't show up when deferred tecnical preview is on

Steps to Reproduce:

1. Place a structure block.
2. Open it and look at its preview when using deferred technical preview.
3. Open it and look at its preview when using simple or other graphics

Observed Results:
When using deferred technical preview, the structure's preview does not show up.

Expected Results:
When using deferred technical preview, the structure's preview should show up.