Thanks for flagging this up. It looks like the elevation data file for this area was corrupt. We've reloaded this and it seems to be working OK now.
John
I am plotting a route in Norway (Uvdal to Fagernes) and am getting a few meters elevation in the first few km, but then a completely flat route for more than 100 km - in a pretty hilly part of the country.
https://www.plotaroute.com/route/605873