It seems that the change to railcard discounted prices takes effect from sometime around the middle of this month. But in some cases it's not just the percentage change on the railcard discount, the undiscounted price is being increased as well.
A weekend super-off-peak return from Cambridge to London with a travelcard and railcard discount will increase from £20.35 on Saturday 14th September to £20.55 on Saturday 21st September (that's a 1.0% increase). The full price ticket is unchanged at £30.90, so the discount has changed from 34.1% to 33.5%, which seems in line with what was expected from this thread.
But the "Greater Anglia only" version of the same ticket is increasing from £14.30 to £16.25 with railcard discount (13.6% increase), or £21.70 to £24.40 for the full price ticket (12.4% increase). Those numbers mean that the percentage discount has changed from 34.1% to 33.4%, which again is in line with expectations, but was anybody expecting the base ticket price to get such a large increase at the same time?