I have been a Rocket Theme member for some time and I have been coping with this issue, trusting that the frontend will acknowledge my Gantry layout settings. It hasn't failed me so far. The frontend displays the layout settings I implement on the override settings page.
Yet. RT developers need to look into why the Gantry settings fail to display the override layout settings when returning to the override settings page. Jakub acknowledged my issue with an earlier version of Gantry and sent me a fix two years ago. I cannot locate the fix.
However, the problem still exists for any Rocket theme I install. Any chance that we can get the developers to have a look? I would be willing to PM login prompts to any of my projects.

Eric
Can you PM me with a temporary Super Admin access please along with what overrides are being ignored and I will take a look to see what the cause may be. Please include the link to this post for ease of reference.