I just found that you have kind of the opposite problem when changing the sorting method. In that case, the search text gets changed to "abc %2B...
Just enter anything with a + sign in it into the search bar, for example: "abc + def". On the search results page, the q-parameter of the...
When you have a plus sign (+) in your search and navigate to the 2nd page of the results, the + gets changed to a whitespace ( ). The problem also...
Separate names with a comma.