Looks like your threshold is really, really close to your VO2max. For instance, it’s interesting that you really struggled with Elephants+4, which is basically 6 minute intervals at 108%, an basically totally nailed Stromlo +3, which is 6 minute intervals at 102%.
On the other hand, looks like the 27oct Elephants+4 was a much better effort…so maybe the previous day’s Tray Mountain effort caused you to bring a lot more residual fatigue into the most recent Elephants+4 attempt.
Anyhow, Elephants+4 is a tough workout, apparently. If I look at the last 20 or so attempts at that workout seems like at least half of those attempts show some sign of cutting the workout short in some fashion.
My advice? Import that workout into WorkoutCreator and add an extra 120 seconds of recovery between each interval. I’d much rather see you accumulate the extra time at the prescribed wattage with extra recovery between sets. It’s more important to get the time under tension than it is to pack the intervals into a certain amount of time.