This article describes about how to enable wf-decoder in web filtering service.

Starting from Junos OS Release 22.2R1, the Web filtering uses JDPI-Decoder support for processing the application data. If you wish to enable the old wf-decoder, use the below command:

set security utm default-configuration web-filtering performance-mode 

The above command requires a system reboot.

For more details regarding this, refer the document: https://www.juniper.net/documentation/us/en/software/junos/utm/topics/concept/utm-web-filtering-overview.html