When I turn a maya camera into a physical camera after the scene is translated it says “Pre-render export”. When this happens it steps through the first frame on the time rangeup until the current frame then it renders.This only happens when the physical camera is enabled. This can take some time with heavy scenes or long time ranges
What are your GI settings? For certain GI solutions V-Ray needs to know the camera path for the entire animation in advance. It should not happen just by turning a camera into a physical one though.
We tested the issue in our enviroment but we could not reporduce it. Could you please send scene file to vraymaya@chaosgroup.com
Can you reproduce the issue with the latest V-Ray for Maya build ?