Cannot access facebook via my laptop or my desktop. Both going through my fios router.. But,,,, I can access FB via my phone!
Impossible.
i would recommend you disconnect your router, leave it off for 5 minutes.
while it's off I would go into the browser settings if accessing that way and clear cookies and cache.
if using the app, uninstall it then reinstall the app. Then turn off both the laptop and desktop and if using a tablet do the same. After all has been shut down restart the router, wait until it's up and functional then turn each device back on till it is fully operational.
Hopefully it will fix the issue.
Good Luck