SKAdNetwork: Error while updating conversion value

Hello!

I make use of the new iOS 15.4 SKAdNetwork.updatePostbackConversionValue feature:

SKAdNetwork.updatePostbackConversionValue(0) { error in
                if let error = error {
                    print(error.localizedDescription)
                }
            }

I am not sure why, but I always see this error message in the console:

SKAdNetwork: Error while updating conversion value: Error Domain=SKANErrorDomain Code=10 "(null)"

The operation couldn’t be completed. (SKANErrorDomain error 10.)

Any idea what’s going on there? What does Error Code 10 mean? Couldn't find anything in the documentation about that so far.

I have the NSAdvertisingAttributionReportEndpoint key with domain (https://api2.branch.io/v1/skadnetwork/advertiser_app) in my .plist.