Unable to Connect to Xbox Live After Latest Update

They really seriously screwed network stack in latest update. For me it started with unability to connect to Xbox Live and now I have similar problems with connecting to wifi

You will be unable to connect to live without the latest update, it is a requirement so no work around in that regard. Although having said that you said you downloaded the update, was it just unsuccessful?

Have you done the test connection to Xbox Live then it should pop up with the update after it is complete and if there are no errors found during the test. You want to instal that latest update because sometimes then don't come with the latest software.
If you reject the update then it won't let you connect to Xbox Live. If you need anything else feel free to message me. Thanks, -Isaac

My xbox is up to date. it has the latest update. The problem on occured after recent xbox live dashboard update. Its weird cause sometimes it connects and other times it wont. Every time it wont I run the connection test and it fails to connect to xbox live
but is connected to the internet. Very frustrating.

In my current setup in which I encountered the issue I am wired to the router. When I tried directly wiring my connection to the modem as Mister Darcy suggested, I connected successfully to Xbox LIVE and received an update which I also downloaded and installed
successfully. Now when going back to my previous setup through the router I again cannot connect to Xbox LIVE. This would suggest an issue with the router?