For Xbox One and Windows 10 this is happening with the new update still. Sometimes after breaking swamp trees, the vines will prevent some leaves from de-spawning. Maybe it would be possible for leaves and (or at least) vines to break down like Chorus Plants when all wood of a tree (or when the top block holding the vines if not connected to a valid block) is destroyed.
Screenshot of issue (Xbox One): https://1drv.ms/i/s!Ald2cMebzOfcjlVEdXWX58lvr2S1
Having a similar issue. I haven't bred horses yet but I did breed a mule and had a similar issue. Here's a video of the glitch: https://youtu.be/Bc0bwaGw0zA
It seems mobs and players just can push baby horses or mules through the fence at the corners and at gates. This is on Xbox One / happened with Windows 10 version too.
Same thing happened with me. Prior to even crafting a cauldron I had only held leather boots that have never been dyed. I made the other 3 pieces and after putting dye in the cauldron and dying the chest piece I got the achievement without even getting the other 3 pieces of armor out.
Have tested with Windows 10 and Xbox One with multiple players; does not work. A lot of achievements are taking a while to register or taking multiple times to register as well, but this one never came.
I have also noticed but only as of v 1.9.0. I had a farm and house set up to have local villagers. I noticed they could pick seeds up but didn't actively seek them anymore, and they wouldn't work their crops. I went to a nearby village and it was the same. All the villagers moved around but didn't tend to any crops.