Google adsense channels cannot be changed for the past 1 week for so. I have tried multiple times with no success.
It is irritating as the channels are essential in tracking the individual ads performanace. I thought that my computer is causing this problem but it seems that the problem lies with google’s side.
Doing a search in google and found out that actually a lot of people is having this problem of unable to change the adense channel and is affecting them in one way or another.
This have already been recorded as a known issue on google side.
Unable to add or remove channels from existing ad units
Details: Publishers are currently unable to add or remove custom channels from existing ad units. It will appear that these changes have been saved, but checking this afterwards under the “Manage Ads” tab will show that the change has not been applied. Our engineers are working to resolve the problem as quickly as possible.
Hope google can resolved this issue soon.