You are correct CA does not tax the services of nonresidents who have no physical presence in CA while performing their services for a CA based company (or division, etc)
and here its tax law
https://govt.westlaw.com/calregs/Document/I39642535B3F14EE08CFD6C4FB3C02AE8?viewType=FullText&origin...
also see this
https://www.palmspringstaxandtrustlawyers.com/nonresidents-working-remotely-for-california-businesse...
