For some reason my thumbnails aren't showing up on Google+ but only for video posts. If I create a picture post, the thumbnail will show up but if it's a video post, it doesn't work.
Side note: they use to show up but now even old posts that use to show a thumbnail don't anymore.
Things I've tried.
1: I always add a feature image (which works on FB)
2. I disabled each plugin one by one
3: I tried using different formats for the featured image (such as JPEG, PNG and a few others)
I'm at a loss, If you could give me any other troubleshooting ideas, i'd be very grateful.