I only just found this out. Some time ago Google took the decision to remove the exact match option from searches. That's the option that used to let you search for "apples and pears" and get matches for the phrase rather than all matches for apples AND all matches for pears. I knew that already but I found out a few minutes ago that searching for '"apples and pears" &tbs=li:1" actually does the search as intended. What was wrong with the old way we shall never know.