Chromecast was working

I run Windows 7 and have been using the Chromecast device to stream to my TV.  Worked great, loved it.

Recently installed Norton 360 Premiere.  Changed from McAfee.

All OK except my Chromecast software can't seem to find the Chromecast device anymore.

I used Norton 360 to turn off the firewall.  Chromecast still can't find the device.

Norton 360 Firewall/Program rules settings for Google Chrome does not include the "auto" option.  But settings for Firefox does include "auto" option!  Odd.

Any ideas?  Thanks, Dave C