Free settings are often designed for 1920x1080. If you render at 4K, you need to lower "Glare" intensity by 30% to avoid halos.
If you prefer to dial in settings manually, focus on these critical effects featured in most top-tier presets: lumion 12 render settings download free
and load your project.
If the preset is too dark (common with "Expert" settings): Free settings are often designed for 1920x1080