Updating post Gutenberg….

I noticed that old posts were not functioning with the lightbox as per this page (http://www.scottspics.com.au/?p=358), so went to update the Photonic link on this post (http://www.scottspics.com.au/?p=364) by creating the new block.
Unfortunately this does not seem to have worked.

I’ve looked through the Gutenberg details and updates for Photonic, however the issue is not something I’ve found.

Any assistance or suggestions gratefully appreciated!

The page I need help with: [log in to see the link]