Upgraded to Photoshop Elements (PE) 2019 from PE5. The thresholding results by both the filter and layer method produce erroneous results that do not match as outlined under the "apply the threshold filter" (https://helpx.adobe.com/photoshop-elements/using/adjustment-filters.html#main-pars_heading_4). The PE2019 results do not match my externally verified images (which have a known value with a TH=128). The PE2019 results also do not match PE5. However, my externally verified images do match PE5.
Was there an algorithm change? Also, why do the different methods produce different results?