Why won't Google Plus automatically upload all photos and videos?

I'm using an Android Phone by LG. Model #LG-D520. It's known as the OPTIMUS F3Q. I want Google Plus to automatically upload every photo and video that I record. My Auto-backup options for photos are Wifi+Cellular. My auto-backup options for videos are Wifi-Only. This morning I took 5 photos and 1 video. I am currently sitting in my home connected to my Wifi network for the past several hours. Yet only 2 photos have been uploaded. It doesn't seem to be uploading the video or the other photos? Why? How to work-around this bug? This problem in such a basic operation is very frustrating. It has plagued me for several months and I have seen other people complaining about it in other forums.