Quick guess: enable trace flag 4139.

You are already running [SP2-CU1][1] so this should work

Note the guidelines about TF 2389 ad 2390 too and also see http://sql-sasquatch.blogspot.com.mt/2013/06/mssql-plan-guides-to-address-ascending.html

(Note, I've not really hit this problem and have not dived in that deep)

  [1]: https://support.microsoft.com/en-us/kb/2952101