My new KICKR no longer responds to changes.
There has been some changes recently to Wahoo's firmware and what is likely happening is your KICKR no longer broadcasts its native KICKR signal. After the update it is likely ONLY broadcasting the Smart Trainer signal (ANT+ FE-C).
What you can do is change your Trainer Type to a "Smart Trainer/Bike" in the Dashboard Settings and get your trainer reassigned.
From the command center go into the Dashboard section then click that red "Assign Dashboards" button. You can also press Control-D to get there quickly.
In the trainer type column change your type to "Smart Trainer/Bike" then assign your Trainer's ID in the other Trainer's ID column...
You can also go into your Dashboard's options and into the "All Smart Trainers/Bikes" tab and enable the "Trainer Control booster" option. Your KICKR should respond quicker with that option enabled, but test it out and make sure all is good. You can do a "Just Ride" workout and manually adjust the slider to feel the resistance changes to confirm things are good.
If you are still having problems then click the "Report a Problem" link in the Command Center's Support section so more analysis can be done.