Rendering artifacts appear in Shader Graph Main Preview after removing Universal Active Target and adding Custom Render Texture Target

Steps to reproduce:
1. Create new Unity project using Universal 3D Template
2. Create new Shader Graph Asset in Project window (right-click > Create > Shader Graph > Lit Shader Graph)
3. In Graph Inspector > Graph Settings > Target Settings > remove Universal Active Target
4. Add Custom Render Texture Active Target
5. Observe Main Preview window

Actual results: Rendering artifacts are visible in the Main Preview window
Expected results: No rendering artifacts are visible in the Main Preview window

Reproducible with versions: 6000.0.76f1, 6000.3.16f1, 6000.4.9f1, 6000.5.0b10, 6000.6.0a6

Tested on (OS): Linux 24.04 (reproducing), macOS Tahoe 26.4.1 (not reproducing)