Apple recently "publicly admited" that there's a known issue that results in signal degradation, which supposedly can be fixed by a software update. Apple has back track now and said that it cannot be fixed by software update.
Apple Care support said "that the update will not fix the issue. Apple said "the incoming software update will not fix this antenna problem, only change the way the phone displays the available signal, make it more accurate," reports Gizmodo.
Although everyone seemed to already know that this was the issue, this is the first time we have heard Apple directly say that the software update will not fix the root of the problem. In essence, they are admitting that they have a design flaw.