Nuke Build with GitVersion

I've been using Nuke Build with GitVersion for a while now quite successfully.

However I've tried the upgrade to v6.0.0 of GitVersion in Nuke and it seems to cause me problems.

I'm using Nuke to package and build various NuGet packages and I use the NuGetVersion property of the GitVersion as follows.

.SetVersion(GitVersion.NuGetVersion)

For some reason it reports both NuGetVersion and NuGetVersion2 as null.

I changed the project to v5.12.0 of GitVersion and it worked fine. I also tried using dotnet-gitversion which admittedly is probably using the older lib and it seemed to work.

Any guidance on what might be the issue?