Inaccurate average and max speeds in Strava
Slopes sends over a lot of data to Strava, including average speed and max speed. Unfortunately it is on them to use the data we send over, and for speeds they aren't. For speed specifically they are currently only displaying those if they come from Strava's own calculations based on GPS data. This is causing things like average speed to look incorrect (they simply recalculate it as distance / time), and for no max speed to register.
We have raised this issue to our Strava partnership contact regarding this issue, and continue to remind them that it is causing frustration for our mutual users.
Edit Dec 2019: In Sept 2019 I was assured by my contact at Strava that they would address these issues, however I've yet to see a fix go live.