Unable to change ordering of Page Three attributes

Hello,

I was trying to change the order of appearance of some Page Three attributes in a subclass of Documents class.

But strangely, I find that after ordering the attributes & clicking on Ok, if I again open the ordering dialog, I can see that the required attribute for which I changed & saved the ordering in the last attempt has been reset back to previous state. This is happening in both Java client & Web client, & for both out of the box and flex param attributes.

I checked & found that some attributes have the field Order visible in the Java client whereas some others are missing that field. And those attributes which are missing the Order field can't be ordered from the selection window. This is for both OOTB & flex attributes.