This issue is caused due to various project templates using the CPU Lightmapper as the default backend. The CPU Lightmapper isn't supported on Apple Silicon, hence the fallback. It's unlikely that we will change the project templates for an LTS, both because it can be a breaking change, and because the GPU Lightmapper isn't considered production ready on these older LTS versions. Given that this only affects Apple Silicon on old LTS versions, we are opting for Won't-Fix.