I have been taking the data on a Wednesday for the 7-day rolling average. I used this site to calculate the average for the last 7 days and got 118, exactly the same as last week. I have added it to my graph and got Excel to calculate the trendline. It is now back to almost exactly the same trendline as when I first calculated it 3 weeks ago.
The points are now further from the line but that is often the case if Physics experiments that plot a graph like this for discharging a capacitor. When the current is low and there are fewer significant figures, the uncertainties are higher and points can be further from the line. This explains why the R-squared value is lower this week.