First day using my new Panasonic HC-V550 camcorder; on a tripod, video recording birds at a feeder on my backyard fence, about 35' away. Camera set on "auto" everything; as I zoomed in to get close ups of a bird, camera stopped focusing on the bird and focused on the tall grass on the slope 15' behind the bird. I could not make the camera return to focusing on the bird unless I "zoomed out" to basic video, when camera would again focus on the bird. Any ideas of what's going on? Is there something I'm doing wrong? Defective camera ? Any help greatly appreciated, by a brand new member here, and new camcorder owner.