had the same issue, opened up a case, and they stated this
We figured out what is deleting the WFA command code. There is a bug where special characters are not encoded properly in the rest request, and so the check is removing anything using redirection operators [>,<] and html tags like <b>,<font>,<br>.
The fix has been developed and will be included in the 5.1P2 release which is planned for December. We are aware this is very close to the end of Flash deadline and will be working to have is available as soon as possible.
5.1.1 just got released, i think that has the fix.