add swarm agent to your firewall and allow acces to your network
why would the lighting builder have anything to do with engine startup?
I have this problem few years ago when I start journey with unreal, idk why but this work;) unreal is problematic engine few weeks ago i get msbuild error and what help? Other name for unreal directory, not ue or unreal only sues_4.27.2 becouse standard name not work 
The editor has absolutely nothing to do with Swarm until you tell the editor to build lighting. Your build errors are because of something configured incorrectly. Without having any idea, Iād guess sharing badly setup VS project files between multiple users.