If you are running V14 of our software, the ICAO code is automatically calculated by SkyView. However, if you mis-entered it before V14, it won't be corrected. Change your tail number up and down 1 digit and it will fix it.
V15 auto fixes it for you.
If you started with V13 or earlier, you had to enter the ICAO code manually, and you could have just gotten a digit off.
There is a different "bug" that can exist with powering on the transponder which is what our support team was trying to communicated. This was fixed in the transponder software version released about a year ago. Make sure your transponder is up to date. If it is (you're on V14 or V15 and it doesn't show an update for the transponder) then this isn't your issue.