Yes, if the next interval is much higher in power than the previous one, it can be very hard to increase the power quickly enough to not lose cadence and along with it lose the ability to even turn the pedals. My best known method in the ERG mode is to start increasing cadence some 5-7 seconds before the power increase. In ERG mode, power does not change when you increase cadence, so it is easy to bring the cadence up. Then, when the resistance increases rapidly, I lose some cadence, but if I started high (e.g., 100 or more), I will probably not drop the cadence too much.
I can easily do a step from 150 watts to 400 watts using this method. It gets a little sketchy when it goes to 450 watts. Above it, it becomes a matter of luck and there is a good chance to fail. One either needs to turn off the ERG mode before the step in power and ramp the power gradually while switching the gears, or create a custom workout with several small steps with increasing power target, 1-2 secs each, for the ERG mode, to be able to ramp up the power smoothly and gradually.
It is neither Zwift nor bike. It is an unnaturally steep increase in the power target - a workout which is poorly written for indoor cycling purposes. The Sufferfest recommends in the beginning of intervals with such large difference in power that they users DO NOT do them in ERG mode but switch to the level mode instead. You just go to the max which you can reach, and this max may very well be below the target. Zwift leaves it up to users how to handle such situations, but to be fair, Zwift does not have too many workouts with such a huge change in power between intervals. Or, at least, I did not run into them yet - but I did many such workouts in The SUF!