My latest ride yesterday night where I was sitting in zone 2 for most of the hour came back with a very high intensity and looking into it further, it seems to have think I was in Z4/Z5 for the bulk of my effort and I am unsure why!
The raw data sent to intervals accurately shows the correct HR zones for the ride (and corresponding intensity/effort). This was also okay last week too, the only difference is that I used my iPad for the ride this week vs. my iPhone but the sensors are the same (as is the data logged being consistent).
It’s kind of hard to say without more information. I don’t know if this was ERG workout or what, but it sounds like FTP is different between platforms but normally changing devices should have the same FTP with TrainerDay. If you can send a link to your web workout or a screenshot from history in our app it should help me better understand.