Increased power but same speed

Anyone experience or know about a bug where you increase power output but your speed barely changes? It’s happened a couple of times now to me. The most recent was on the Tempest route just approaching the route end. Increasing from ~150W to 635W only resulted in a .1kph increase.
You can see it at about 89:23 into this activity. I increase power at 90:11 but speed stay almost identical. activity/944267528413134848 MacOS 12.0.1, Ant+, Tacx NEO 1.