Since it's introduction, Movies Anywhere has proven to be a fairly robust system that works well overall; however, there have been reports of issues with everything from movies not porting to/from MA, movies porting at the wrong definition and other similar issues.
Personally I have experienced a small amount of these errors myself, and since we just passed the 3 month mark I feel that it's time that I start addressing perceived issues and see if I can get them resolved.
One early issue has already been addressed and fixed, the Disney movie The Lion King, which was not porting from Disney Movies Anywhere to Movies Anywhere for a large number of users, and did not port for me as well. A few back and forth emails between myself and Movies Anywhere and some patience and that issue was successfully resolved and now appears at Movies Anywhere and all my connected services.
To work on additional issues, I've decided to approach them in chunks, and for my first project have decided to try to get Apple to fix any existing SD titles that correspond to HDX titles in Vudu and that are also MA compatible. I emailed Apple a couple days ago and am waiting to hear back.
I will update this thread as I go along and hopefully this information will help someone else by pointing them in the right direction to fix MA issues.