I've used Athletica for two years now and never experienced that the set intervals and total workout time don't match. Maybe you are not reading the workout correctly?
Also, you need to go to your Garmin and make sure your Garmin settings are correct and match the zones with Athletica. Athletica can't push the zones to your watch. So if you have done the test week with Athletica and got your training intensity zones adjusted, then you still need to go to settings on Garmin and change the zones there. Otherwise you will get those discrepancies with Garmin. Hope this helps :D

how much nuance can you add the program? say i'm training for a half ironman, but it's got a hilly bike. with a human coach i'd simply say, "hey, hilly bike - let's push strength work and climbing a bit." can the AI handle that kind of input?