Issues with climbing resistance

I recently purchased an Elite Digital Interactive trainer and have been using Zwift through an ANT+ connection for the past month.  This morning I rode the 2x20 FTP Intervals on the PRL Full course and noticed that while there was resistance on the flats, I didn’t detect much additional resistance on the climbs even though speed reflected the grade changes, but power during the intervals held steady.  I would have expected power to spike during the climbs.

anyone else experience this?

If you are in WORKOUT mode then the trainer will not follow the road grade. But it will still base your speed on the power you produce. so you may be riding at 150W on a flat road you will be going 30km/h but when the road goes up and you still do 150W then you speed may be 8km/h.

The nice thing is you can concentrate on the required power without changing gears to stay in the zone.