Secondary Audio Program

I am watching an MLS Soccer match that is being broadcast on KWNL (Univision station in Ft. Smith Arkansas, cable channel 11 on my Cox lineup). At halftime the announcers said that English commentary was available on SAP so I used the menu on the Cox remote to switch to the secondary audio but when I did all I got was silence. I'm not sure if this is an issue with KWNL not broadcasting the SAP or if Cox is dropping the SAP for this channel. If it is Cox I would appreciate it if you could correct it.