Open Threat Extraction Gateway object - go to Threat Extraction pane - refer to Delete stored original files older than ... Days and set the needed value! Other important information for R77.30 TX can be found in sk106249 and sk122099.
Any update ? Did my suggestion not work for you ?
No, The default is 30 days, and can't be change in the Sandblast cloud product.
Retrieving data ...