The good news is that it looks like NVIDIA has since fixed the problem, according to a post in the forums. According to the post, it reads, “We received reports of some users experiencing Wi-Fi functionality issues after applying Software Updates v1.1 (SHIELD tablet K1) and v4.0 (original SHIELD tablet). To avoid any potential issues, we suspended the OTA pending further testing. At this time, we’re confident we have corrected the problem and are releasing a new Software Update.”
Note that this update will also be applicable to the NVIDIA Shield Tablet K1, so if you own either device then you’ll want to keep an eye out for the update. Based on the statement posted in the forums, it sounds like the update is good to go. If you haven’t received any notification informing you about the update, you can try to pull it manually by going to your tablet’s Settings -> About tablet and see if you can pull it there. If not we suppose you’ll just have to remain patient and wait for it to be released.