Hi KP,
This has always been a problem. I take it you are simply making a backdated change to a value in a UDT. Retropay relies on triggers that are set by changes to, in the main, the person assignment or element entries. As nothing has changed against the person retropay doesn't know who to re-calculate. With Retropay by Element you could always get round the problem by manually creating an assignment set. Not sure how this would work in Enhanced Retropay.
Delboy