Connection?

today i did an organised group ride, and the effort wasn’t reflected in the output. i was showing 3+ kw/pkg and doing 25kmh. never had this problem before. i stopped pedalling and my avatar continued on @ 20kmh. i connect using a laptop and companion app bluetooth to pick up the trainer etc. the only change is i recently added an ant+ so i could get the heart rate monitor also. I have not changed any settings in zwift from when i first started using it.