Leaving platform 2 at Reigate when the signal is yellow, I get a brake demand. This is because the TPWS grid is after the signal, and must be reading the data from the red signal ahead. The grid needs moving so it's detecting the state of the signal on the platform..
This happened to me as well with service 1R53. I departed Reigate platform 2 on a single yellow. As soon as I entered the 15 mph crossover that leads to the Up Reading line I got a TPWS brake demand.