Tested on a clean install of Obsidian with no plugins installed
Current version: v1.4.4
(Installer version: v1.3.7)
If you add a card to the Canvas and make a link to the note in this card, then when you click on this link in the note structure panel, the headings disappear, but if the same note is added to the Canvas as a note, then when you click on the link in the structure panel, the structure is displayed correctly
I think this is a bug that needs attention!
In the video, everything showed in detail the moment of disappearance of the headlines is clearly visible