the reason you are likely being told it is in violation is because the term "dagger" is used repeatedly in the penal code (12020 pc). the common definition for a dagger is a double edged knife. however, there is no mention of this in the penal code. dagger/dirk is ANY knife carried concealed and readily available for use as a stabbing weapon.
per the penal code, you are not in violation if carrying your kabar openly in a sheath.
in los angeles county/city, no fixed blade may be carried if the blade length exceeds three inches, unless you are coming from or going to a legal occupation/recreation in which the knife is to be used.