For more than a week, I've been having the same issue. The same search, using a tag, keeps showing up when I launch Evernote.
So far nothing is working:
I uninstalled and reinstalled Evernote. That at least solved the issue that it would take numerous tries to actually get out of that search. At lease now, I can remove the tag, click in the search bar and start a new search.
I tried Mike P's suggestion - closed EN, stopped all processes in task manager, and restarted my computer. And the darn search showed up again! I'm going to reach out to support.