They have a presence in CA, but HQ is Israel.
Strange routes would not surprise the veterans as there are some places and some roads which got really messed up early on, and without community members stepping in to fix problems, or users to just drive the areas, then they may not get fixed very quickly. Mapping is done by the community.
I made a 100% complete update of US101 through OR and into northern CA a few months ago, but haven't ventured further south. Yet.
For your specific issue, I am sure there is a good reason (disconnection roadway, bad intersections) which is preventing a proper route from being created. One thing I do is drive the way I know is correct and watch Waze continually tell me to go another direction. When Waze finally gives you a proper route for the place you are it, it is highly likely that the last intersection you went through, or segment of road you just passed is a culprit. Please submit a map update request when you are at this intersection (next time?) and take some time (pulled over, or later via the Live Map on this site by clicking on the spot and Report Problem) to give details as to where you were coming from/going to (roughly, we don't need address detail all the time), and when Waze gave you a correct. A community map editor should be able to respond.