With increasing frequency, a number of Pixel and Pixel XL owners are encountering a bug with the Pixel Launcher and its capability to quickly search Google from the shortcut. This issue seems to completely disable the ability to use the Google Search pill to perform any sort of query.
Those with the issue note that their search history does not load upon pressing the pill to expand it. Additionally, suggestions do not load as users enter a query nor does it actually complete a search after hitting enter.
Device reboots appear to completely alleviate the bug for some, though others report that the issue quickly returns. Other users suggest stopping the Pixel Launcher and the Google app to solve the problem.