When you edit a play, you MUST remove it from your playbook. If you do not do this, the play remains unedited in your playbook. I had a play where I got sacked EVERY time and I couldn't understand why. I edited the play (finding out why it was a sack every time... my own stupidity), played another 5 seasons, but the same thing happened. I went to the playbook and went to edit it again, but it was not the new play I edited to, but the original play with the original problem.
So, I removed the play from the playbook, and at the same time I created a playbook for the 2 minute offense, and this play was added (I was not thinking well, I guess). Well, after 5 more seasons, I found the play was rather successful. I went back to look at the play in the new playbook and it was the new, edited version. So I added it back to my main playbook and after more testing it's working as expected.
The moral, again, is that when you edit a play, you must remove it from the playbook... then put it back. It is not edited in the playbook, but in the main play section, and does not update when edited.