Xcode 11.3 not opening projects

Xcode is refusing to open any projects, every time a project is opened the spinning wheel starts and Xcode freezes and has to be force quit. On a rare occasion the project might open after a minute or two.

I have undertaken many things to rectify this, some more drastic than others:

1. Removed all derived data.
2. Removed all of the /Library/Developer folder.
3. Fresh install of Xcode
4. Fresh install of MacOS, removing all Beta breadcrumbs (this was ok with a new project, as soon as I opened an older one, back to square one)
5. All the above again

There are many threads about issues with Xcode, but none that has a reputable fix; really want to get this nailed.

After further investigations, some release notes were found for Xcode 8.2.1 running on macOS Sierra:

Known Issues

• When an Xcode project is stored in iCloud Drive, Xcode does not automatically detect iCloud Drive sync conflicts for projects or for files involved in the build. Note that the Documents and Desktop folders can be stored in iCloud Drive on macOS 10.12. (18161353)

• Opening Xcode projects and workspaces stored in iCloud Drive, or changing source control branches for an open workspace or project stored in iCloud Drive, may sometimes cause Xcode to hang. Note that in macOS 10.12, your Documents and Desktop folders may optionally be iCloud Drive locations. (28212905)

There seems to be a similar issue with Xcode 11 running on macOS Catalina.

So to solve the problem above, move any of your projects away from a location that is sync'd with your iCloud Drive, so not on the Desktop or in your Documents (if you have this activated)

I have tested this and all is super fast and back to normal.