A hard-to-track and not always an issue bug is impacting many that have the Google Pixel Launcher running on their Pixel phone. The issue is around searching when you tap the search pill at the top of the launcher. Some have reported that when they tap it, their search history does not display and suggestions does not load.
The issue does not seem to be universal. Some users have had no problem (I fall into that category) while others have found that a restart of their phone resolves the issue, others haven’t been able to get it resolved with a reboot. Equally, it is not clear if the issue is related to the recent update to the Pixel Launcher which rolled out earlier this week.
The frequency of the bug appearing seems to be increasing as more people do get the update to the version 7.3 update of the Pixel Launcher. So far, Google themselves have remained quiet as they likely are trying to uncover the actual issue at hand.
As for a fix, you can always try to simply reboot your device to see if that sorts it. You can also clear the data in your Google app by going to Settings>Apps>Google App>Storage>Clear Cache as that too has worked for some (especially if you are having issues with Google Now cards not appearing too).
If you are having issues, the best way to get the information to Google is to go to the Google Product forums for the Pixel lineup.