Alas at Ashtead, it was announced that an earlier SWT▸ service had failed at Stoneleigh and was blocking the line. My train stopped there for over 20 minutes before continuing to Epsom where it was terminated.
I was on that failed train. It arrived at Stoneleigh on time and then "lost power". After about 30 mins we were told to get off and take a train back to Epsom and then take a Southern to Victoria. Because of all the trains terminating at Epsom we had to wait another 15 mins or so for a platform to become free. Got into work 90 minutes late.