It didn’t happen to me, but another rider. Was on the first little climb with another rider riding side-by-side. We both were fast approaching one of the bots ahead of us and the other rider came upon it first. I saw their power drop instantly to 0 and then saw them drop off the back while I was able to proceed. My power was unaffected. I watched the stats for the other rider and noticed he/she start up again, but the power/weight ratio seems much lower than when we were riding together.
I had the power drop to 0 again for me later in the ride when a bot came up quickly from behind to pass me. It happened on the steeper section of the downhill when the bots seem to accelerate quickly.
I think the power dropout issue is due in part to the simulation being unable to discern riders that fast approach one another and seem to occupy the same location for a brief instant. I don’t know how Zwift determines the location of each rider in the simulation, but it seems that the program doesn’t allow for riders to have the same location.
I can see why this has been a hard issue to solve in that it requires a unique set of circumstances for it to be repeated.
Even with the dropout issue, I still had an awesome ride. Hats off to the Zwift folks for creating such an amazing program!