Symantec DLP 12.0 onward, data within Master Templates will trigger incidents when Slide Master is more than one page.
Alternative workaround to capture Slide Master data on single PPT page is to modify formats.ini
formats.ini is on Detection servers and is located In \SymantecDLP\Protect\plugins\contentextraction\Verity\x64
Add the following to formats.ini:
[Options] MasterslideText=TRUEKeep the remaining options the same. Then save the file and restart the Vontu Monitor service.