If you have Norton Antivirus, then ignore Windows Defender Antivirus, use what you learned from reading that thread, and apply the same concepts in Norton Antivirus.
I use the latest (new) Norton 360, which includes Antivirus and Firewall, so all my settings are in Norton. Do you have Norton Firewall as well?
Windows Defender does actually still operate to some degree when you use a third-party security application, as we do. For example, when you boot up the PC it is Windows Defender that does the protection until Norton loads up and Windows Defender passes off the protection responsibility to Norton. That can be confusing, and annoying, at times, because you might see a message from Windows Defender when Norton should be doing the protection.
Regardless, as you are using Norton, do not turn on Windows Defender Antivirus. If you are using Norton 360 which includes a Firewall, do not turn on Windows Defender Firewall.
Do add or check the exclusions in Norton Antivirus and Firewall as per that thread.
Norton has pretty good Help, Manuals, and User Support. Use them.
Also, even though you have just updated, run Windows Update again, once or twice, and reboot the PC after each update. Reboot twice after the final update. That allows Windows 10 to complete all updates and check if anything further needs to be updated. It may be overkill, but I find it fixes some issues sometimes.