Quick answer: Unity Shader Graph Time node showing zero during lightmap bake? Editor time tracking paused during bake; shaders sampling Time show static values - use a custom uniform.
Animated material in a baked scene; visible artifacts where shader assumed time was advancing.
Skip animated shaders for baked
Mark static. Bake doesn't run them; runtime does.
Or use Time alternative
UnityEditor's UnityEditor.Lightmapping.bakeStartTime. Custom uniform.
Audit baked materials
Each material in a baked scene: time-dependent? Mark accordingly.
“Bake context is special. Time-dependent rendering may not be relevant.”
If your baked scenes have animated shaders, the bake-time handling is mandatory. Document.