I encountered the same exact thing when trying to do a high-res screenshot. The viewport preview shows correct camera focal length / FOV, and then rendering it results in closer zoom in my render. Plus, the horizontal angle changed a bit too, by about 15 degrees or something, as though the camera had swiveled to the right + down somewhat. I think there’s a second set of camera parameters that are involved in causing it, or two or three parameters in the cine camera actor’s details panel are connecting wrong and/or canceling the other setting(s) enough to result in the wrong zoom. I suggest modifying Aperture and/or F-Stop slightly to see if it corrects it, and potentially Focus Distance.