Has there been an update to the search engine this week? Search parameters automatically change...

[cfy]

As of Thursday, 3/28, search results changed. I had been able to set parameters such as category and search-by  for a number of searches by setting them for an initial search and then simply changing what I was searching for. Now search-by keeps changing from newest to best every time I change what I am searching for. I used to be able to search for boots or coins in all categories; now the search changes the search to a specific category most times, requiring me to manually alter the search. I didn't make any changes to my settings on both computer and Ebay.  Has anyone else experienced similar problems?