Welcome to Seven Forums,
Have you already tried a Power Cycle
If that didn't help at all, take a snap shot of the Mac Filtering page, paste it on to MS Word or Wordpad and save it, then Disable Mac filtering for now. Test your internet connectivity after. If all goes well, then you may do the Mac filtering again.
Still No-Go, proceed to update your router's firmware. You may download the firmware from the Manufacturer's site.
An udate will be appreciated.