RTX 50-series GPUs aren't supported by the Iray renderer in Daz Studio 4.x, which uses an outdated Iray version (2024.0.4). The newer Iray 2024.1 adds 50-series support but was recompiled with a different C++ standard, making it incompatible with DS4's codebase integration. That's why you have to choose Daz Studio 2025 Alpha, which integrates Iray 2024.1 natively, enabling full GPU rendering on 50-series cards.