Have you compared to a third source? It could be that the kickr bike is the more accurate reading. (I get that you’re trying to match so things don’t appear ‘cheaty’ But it would be in your favor to correct to the bike’s higher numbers if those are more accurate.)
I have 3 srm, and like assomia, they are all calibrated using a 10 kg weight. I am doing dual recording time to time with srm and assioma to validate. All these powermeters are in a 2% range max.
So i am very confident assioma are returning correct value. Looking also on zwiftpower, i can see most of kickr bike are in same situation.
Have you tried talking to Wahoo - they should be happy to replace your Kickr bike given its so far from the stated +/-1% accuracy. They may even have a firmware available/in the pipeline if it’s a widespread issue.
We cannot put link in comments, You can check by yourself on zwiftpower. Look at ZRL results last tuesday and you will find a lot of result for kickr bike. Often 4-5% more
My main concern is that Wahoo is not offering to customer a way to change offset by themselves like srm,assioma, quark… are doing for instance.