After a Civi update from 4.x to 5.8.1, quicksearch stopped searching on email addresses when using the name/email option (the first and default option in the dropdown). It returns no results, and comes with the message "name/email not found. Did you mean to search by name/email instead ?"
If we use the 'email' option from the dropdown list, it works as expected.
The search preferences look like before. The first quicksearch option, "Name/email" can not be unchecked there.
Under the hood, the option is called "sort_name", both in the preferences screen and in the quicksearch widget itself (however, as soon as you start to type, you are typing in another widget, without a name, but that could be voodoo)
After clicking enter, which takes you to the advanced search, it shows the results as expected, including matching emails (Results for "Name or Email LIKE - 'pike-foo'")
Is the sort_name perhaps cached somewhere in 5.x , and do I need to build/rebuild it ?