Regarding the issue of sodium chlorate in sodium hypochlorite

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The sodium chlorate contained in our sodium hypochlorite can have its concentration determined by adding ammonium ferrous sulfate and then performing back-titration with potassium dichromate. What I would like to ask is: if sodium chlorate is present in sodium hypochlorite, when analyzing the effective chlorine using the method of adding potassium iodide and hydrochloric acid, does the chlorine from sodium chlorate also get included in this measurement? Additionally, a sodium chlorate solution containing 100 g/L of sodium chlorate was prepared; if converted to chlorine in the form of sodium hypochlorite, this would correspond to about 33 g/L. However, upon adding potassium iodide and hydrochloric acid, the solution turned only slightly yellow. Does this indicate that the method using potassium iodide and hydrochloric acid cannot be used to analyze the chlorine content in sodium chlorate? I would appreciate your advice.