I was doing a workout uploaded from Training Peaks (my workout of the day). It had multiple different intervals. In one of them where it has 9 repeats of a “high” and low interval, it didn’t properly switch twice. So the high interval carried into the low one and the trainer kept me at the higher wattage (despite the target listing the right wattage). And the second time it was wrong was the opposite.
It didn’t do it every time.