Watts stream not matching max watts of activity

Hey 👋

Recently started experimenting with API, and wanted to fetch watts stream for cycling to calculate different metrics on my own (1sec power, 10 sec power, 1 minute power, ...).

Endpoint: https://developers.strava.com/docs/reference/#api-Streams-getActivityStreams

What I noticed immediately upon fetching data, is that I was not able to match anyhow 1-sec best power. Strava app showed me 1-sec power around 600 watts for the ride, but when I fetched the stream - the highest number was around 270.

I read about it a bit, learned that Strava might be downsampling on longer rides, but what feels weird is that this ride was 45-mins long, and my strava app even shows 15-sec power around 500. Now I’m left wondering if streams endpoint is of any use, since I can’t rely on the returned data. It’s not an isolated case, I encountered same issue on another activities I checked. 

How I fetch the stream:

url = f"{config.STRAVA_API_BASE}/activities/{activity_id}/streams"
    params = {
        'keys': 'time,watts', 
        'key_by_type': 'true'    
        }

Anyone had similar issue?

Thanks!