Facebook issues

Hi Guys

There are a few issues I am having with facebook sharing, everything used to be fine but the last few days has had problems, not sure why, I haven't changed anything.

So the problem is some of our posts, not all of them, can't share properly to facebook.

Some don't give us the correct photo, some can't share at all, some you need to press the share button twice in order for it to work.

These are the problem posts
http://hellomk.com/food-tw/food-tw-food-and-drink/2016-05-05-11-45-25
http://hellomk.com/food-tw/food-tw-restaurant-reviews/12
http://hellomk.com/travel-tw/travel-tw-destinations/8
http://hellomk.com/food-tw/food-drink-tw-recipes/18-1 - this one is giving us a 400 problem code


There are many other posts that have to be clicked twice to see the image that people are to share, is this a facebook problem or problem with my site? If the post is confirmed as shared then the image show sup on facebook, but not within the sharing pop up box that come on our site.

It does seem like it is only the last few posts that are having problems, everything else is just a click on it twice post.

Please let me know how I can fix this.

Thanks

Alex