Has anyone found their search history disappears by day(s) at a time?

I have 2 imacs. One is a 2009 the other is a late 2013. Both were purchased as brand new. Both currently have Yosemite as the OS. It seems like since I installed Yosemite on the older iMac I found that my Safari search history, which went back a year, was effectively being "eaten". I would lose a day or more of prior search history. Even though I tried using Manual and After 1 Year in system preferences for search history removal to see if either would stop the problem nothing changed. It got to where I had less than 2 months of search history, where I had a year before, within just a couple of months.

I decided to get a second, newer iMac which came installed with Yosemite and I've recently found I'm starting to see a similar problem. I've spoken with multiple Apple support people and I recently had one state this is a known Yosemite problem? Has anyone else run into this and would upgrading to El Capitan fix the problem?