The 2nd and 3rd screenshot from P2 below show the same spectrum only with and without Cl added to the quantification algorithm and fitted spectrum line. I would agree that the Ag LI peak does seem abnormally high (indicating that there could be some Cl present here). But the proof is thin… I would advise to search for an alternative technique to confirm the presence of Cl. XPS/Auger or maybe ToF-SIMS.