I have discovered what appears to be an undocumented and highly disruptive behaviour with Lucidchart master pages.
I built a detailed process map using assisted layout. Each process step has tags applied to the shapes representing the systems used at that stage. These tags are critical metadata, not decorative labels. They are used for filtering, analysis, and downstream process work.
I later converted the base map into a master page so I could reuse the structure across multiple pages. When the master is applied to new pages, all visual elements (shapes, icons, text, layout) are correctly propagated, but all shape tags are missing on the applied pages.
This behaviour is extremely unexpected:
• Tags are attached to shapes, not pages
• The shapes clearly exist on the applied pages
• Icons and other visual indicators propagate correctly
• There is no warning that tags will be lost
• Documentation does not state that metadata is excluded from master inheritance
As a result, a significant amount of structured information is silently discarded when using master pages, making master pages unusable for process maps where tags represent systems, controls, or attributes.
This feels like either:
1. A bug in how master pages copy or reference shapes, or
2. A major functional limitation that is not documented and breaks real-world modelling use cases
Either way, it prevents using master pages for any diagram where tags carry meaning rather than being optional labels.
