Thanks for the reply.
I was using VS 2022, using the MSVC v143 2022 compiler v 14.39
After fumbling around with different compiler version, I found this error during a compile:
UnrealBuildTool has banned the MSVC 14.39.33519-14.39.99999 toolchains due to compiler issues. Please install a different toolchain such as 14.38.33130 by opening the generated solution and installing recommended components or from the Visual Studio installer.
So I installed 14.31 as per this thread: UnrealBuildTool has banned the MSVC toolchain but I still get the error.