Menu changes in Ghost CMS not propagating to Gatsby correctly/fully

[eltel]

Issue Summary
Updating navigation items in ghost cms does not function correctly in Gatsby front-end

To Reproduce
It's on a live site, published here: www.timeline-music.co.uk via Vercel (I had similar issues in the beginning when I tried with Netlify, so I don't think the hosts are the issue). I simply create a new page in Ghost, add it to nav menu in design - works fine locally but some weird caching issue is occurring on the live site where only the old version of the menu is showing (also some old, DELETED background mages) - even a browser cache clear and hard refresh seem not to work. Opening on anew device works in some instances.

Steps taken to resolve
Included onServiceWorkerUpdateReady for gatsby-offline to update cache on page load, deleted cache manually locally, added gatsby-clean to build script.

Technical details:
Ghost Version: 3.2.0
Gatsby CLI version: 2.12.107
Gatsby Version: 2.24.26
Node Version: v14.14.0
OS: Linux Mint 19

Any tips would be greatly appreciated as this is n fact a live site and we urgently need this page to be added.

Thanks in advance!

**Just for clarity - "Live Broadcast" is the new navigation tab added in post and it is not appearing on apps already installed and for people who've previously used the site/app (PWA)

[eltel]

So, it appears I'm going to have to hard code this page on the front end, removing it from the CMS - which kind of defeats the purpose of having a CMS? If anyone can get back to me on this I'd appreciate it as we've invested a lot in data entry and feel that Menus not updating in accordance with the CMS menu is indeed a bug that needs resolving. (To be clear, almost everything else is updating on rebuilds, just not the menu)

Thanks

Terry