@Eoin , @xspy , thank you again for reporting this.
It turns out, other macOS versions are also unable to connect in the 2.0.03 release.
See the explanation from OZ in another thread:
Until this, please use the newest Release Candidate of the 2.0.03, which still uses the older BSL Library:
https://release.lightburnsoftware.com/LightBurn/RC/LightBurn-v2.0.03-RC-4/LightBurn.V2.0.03-RC-4-0a9076b.dmg
It will install on your system as a separate “PreRelease” version of LightBurn, which has it’s own set of preferences. This means it will not affect your standard installation of LightBurn at all, but it will also not have any personal customizations applied as in your current installation.
The installer should automatically ask if you want to import a copy of your standard release version preferences - you can also use the User Bundles feature to move over your preferences at any time later, if you choose.