Very slow displaying PDFs modified/generated in Javascript after Feb. Update

Hello this is breaking our PDF workflow after the Feb. Acrobat DC update. We are using Action Wizard to invoke Javascripts to loop through open PDF documents and extract pages containing certain phrases. Here is the code fragment:

        for (var p = 0; p < src.numPages; p++) {
            // iterate over all words
            for (var n = 0; n < src.getPageNumWords(p) - 1; n++) {
                if (src.getPageNthWord(p, n) == "Search " && src.getPageNthWord(p, n+1) == "Phrase") {
                    pageArray.push(p);
                    break;
                }
            }
        }

        if (pageArray.length > 0)
        {
            var oNewDoc = this.extractPages({nStart: pageArray[0], nEnd: pageArray[0]});
            for (var n = 1; n < pageArray.length; n++) {
                oNewDoc.insertPages( {
                    nPage: oNewDoc.numPages-1,
                    cPath: src.path,
                    nStart: pageArray[n],
                    nEnd: pageArray[n],
                } );
            }      
            oNewDoc.saveAs(tgtPath);
            src.closeDoc(true);
        }

Can someone help me on resolving this? Also, where can I find the installer for older version of Acrobat DC, pre Feburary 2021?