Checking over my travels in CA, I noticed that CA1 between exits 66B and 68 of US101 near Ventura is missing a shaping point that US101 has, breaking the concurrency.
Also, OSM and GM have a different routing for CA1 at Oxnard (along Rice Ave bypassing the city, rather than Oxnard Blvd through it). Streetview doesn't have any CA1 signs along Rice (even July 2022 imagery southbound), and there's a few on Oxnard (though the imagery is older) albeit not at the ends, so you are more likely to be right than the maps, but there might have been a recent relocation.