I have been riding in B races with an FTP of 258 and a body weight of 144. After updating the firmware I have lost about 15% of my power. I have tried to correct the problem with customer service but they have not been helpful. It is frustrating since I’m unable to compete on the same level. My version of hub doesn’t have the wrench icon to recalibrate. I have tried to recalibrate by riding for a while then not pedal for 5 seconds. It is not helping with the issue.
Are you dual recording with power meter pedals? If not, how do you know you have lost power due to the firmware update, maybe now it is just accurate? The only way to know for sure is to test with an acceptable alternate power source like assioma pedals or other accurate power meters on the bike.
I’m only using the power meter on Zwift. For 15 months I have an FTP of 258. I can come close to that right now. Also, I did a Vo2 max at the university near me in their sports department and the numbers were very similar to what I was doing on Zwift. After the update, my FTP is dropping off noticeably.