Alpe du Zwift Climb Power Issues

I’ve had unusual power issues while climbing Alpe Du Zwift. I ride Zwift using a Hammer trainer. The firmware is up-to-date and the trainer is calibrated.
On two separate rides up the mountain the power level appears to drop off after I get up past turn 8. Up until that point, I was averaging 220 - 230 watts per turn segment. After that the wattage levels that I could maintain on 8, 9, or 10% grades were decreasing. The decrease wasn’t due to being tired, although I was! I had to shift my cassette to a harder gear to get close to the watt levels I was maintaining in easier gears. In fact, it felt like the trainer or the game was maintaining my watts closer to 200 or less.
This happened back on November 29 during the event ‘The Alpe Dash by Herd Racing League’. I thought that active category enforcement had turned on during the ride. This started sometime after turn 10.
This happened today (Dec 13) as well when I did the ‘Road to Sky’ route. The wattage decrease began during turns 7 and 6.
I also recall this happening last year during the Tour de Zwift, but didn’t think about until I rode the Alpe again as described above.
Anybody else notice this?? Maybe my trainer was tired.