Stubborn alt tags

I have tried to add alt tags to most of my images on my site for 2 weeks with no success. I have used the media library edit, the text editor and the visual editor. None of them work. They never save.

I then deactivated PageBuilder. I was then able to save the alt tags in my text editor. They finally saved after I deactivated PageBuilder. I then reactivated Pagebuilder and they magically were still in place. It seemed like I was making progress.

The puzzling question is, why does this “alt check tool” inform me that I do not have any alt tags on my images?
http://www.feedthebot.com/tools/alt/