I has the same last night. Left Perth with 95% est at Tebay 25% over the next 30 miles the Tebay estimate lost 1% for every 3 miles driven.. ended up being 10% lowest.. then started to climb again I got there with 18% which is what ABRP predicted. I didn't get any rain to speak of, but the dry wiping was terrible.
This was the first long distance run with AP since August and I found the car very jittery .. hunting between the lines for the correct spacing with sudden small changes in direction. Almost every motorway junction with the 2 arrows on the road produced an indecisive brake and jerk to oneside needing to be counteracted. There was one.. I can't remember, somewhere in South Scotland where if I hadn't intervened, I'm sure we would have taken the exit the change in direction was so great.
I'm sure there must be something about those Scottish arrows, thicker or thinner as its almost exclusively in Scotland where I get that problem. Mostly M74 South of Glasgow.
Other than that, not too much phantom braking.. one biggie beside a truck which might have been drifting into our lane and another with a motorcycle going between cars. This was a tiring 550 mile drive, not at all relaxing like they usually are.. this latest iteration is a backward step overall for me although positives were the steering nagging pressure seemed lighter and the lane capture was not as violent.. or perhaps I've got used to positioning the car better? Fingers crossed the next one is soon and fixes the problems.. I'm heading north next week. Currently 32.7.