Running the Faversham to St. Pancras route with the 395 and the wipers die roughly a stop from Rochester (a Guided Journey route). Had them at 10% until they stopped and nothing works except for manually moving park left to park right (Single Wipe doesn't work either). I see from searching this has been an issue with various routes throughout the years on various platforms (including this specific train and route) but no recent report of this specific issue. So here I am. Reporting it.
Strange... They said they fixed that a couple of weeks ago. I personally had it once (it was on a 395, like you), but that was before the patch so... Well done for reporting!
I think the wipers are randomly stopping working on all trains. I’ve certainly experienced it on at least four different trains. I think it’s a global bug. It has always been a bug but I think it has got worse, plus more people may experience it more often now with dynamic weather too.