An adjuster shall have authority under an adjuster’s license only to either investigate and negotiate settlement relative to insurance claims, or apply the factual circumstances of an insurance claim to the insurance policy provisions, or both, to the adjuster’s principal upon claims as limited under RCW 48.17.010(1) on behalf only of the insurers if licensed as an independent adjuster, or on behalf only of insureds if licensed as a public adjuster. An adjuster licensed concurrently as both an independent and a public adjuster shall not represent both the insurer and the insured in the same transaction.