Hi again Tom,
I had a look at the Halvfems and Orange Unicorn workouts and didn’t see anything out of the ordinary, though admittedly one can’t see information beyond a visual representation of the segments and the wattage targets.
If you’re having a hard time reaching your wattage targets at low cadence, it almost sounds like ERG mode is not working correctly for you. ERG should increase your resistance to help you reach the high wattage targets at a low cadence. For example, if the resistance is very high, you won’t be able to pedal very fast (low cadence), but pushing against the difficult resistance should generate higher wattage. If that is not happening for you consistently, then it would appear there’s a technical issue preventing ERG mode from working the way it’s supposed to work.
Also, you’re not changing gears during your rides, are you? If you’re using ERG mode, you shouldn’t need to change gears on the bike. Just set your bike in a neutral gear, keep an even and steady cadence, and let the smart trainer do all the work for controlling your resistance.