Project Targets not adjusting to reflect progress vs deadline

I’ve had this problem for a long time, but thought it might be my old and tired computer that was the problem.
Now I’ve bought a new computer, and I still have the same problem.

The Session Target doesn’t adjust to my progress. If I speed ahead or fall behind my original schedule, this doesn’t reflect in the Session Target. If I speed ahead, the daily target should steadily decrease, and if I fall behind, it should increase to reflect how many words I need to write every day in order to hit my deadline.
For example, I’ve now been on 799 words per day for a week, despite falling behind my schedule. Only when I opened Options did it catch up and change to 807.

The counter does update if I go into Project Target Options – or, strangely enough, if I open the same project on the Mac, and then again in Windows. (It works flawlessly on the Mac, btw.)