by AndiS » Fri Aug 30, 2024 9:33 am
Glad it worked right away.
Otherwise, you would have had to look for something on "UTM zone" in that file. The value should be 30U for most of England and Wales. However, I am not sure that this field still exists in these files. There were some changes on that in the course of (distant) history.
Yes, you always have to close and restart all programs for all sorts of fundamental changes in the data. That holds for most pieces of software. Changing the route origin is not something you do on a routine basis, so the software needs a bit of a kick and quite some time to recompute whatever coordinates depend on the route origin.