I use Firefox for Mac at work. I have to use Firefox as my default browser because one of the cloud packages we use only works on Firefox. I can set my basic preferences (home page, preferred search engine), and when I close out and restart the next day, I'm back to default. Sometimes it will remember preferences for 2-3 days, and then reset to default.

Since we also operate on the Google drive, continually having to reset my home page to google so I can get work done is maddening. Sometimes it happens at random after being away for an hour, I'll find firefox closed, and on reopening, it's reset again.