Problem with PPPoE client and Facebook

Hi,
I have a strange problem. I have a CCR1036 as PPPoE server and some RB951 as PPPoE clients.
PPPoE server IP is 10.10.0.1. My strange problem is that during the day, pppoe clients cannot reach facebook at all and when they ping facebook they have as result:

Reply from 10.10.0.1: Destination host unreachable

rather that:

Reply from 31.13.93.3: bytes=32 time=82ms TTL=85

If I restart CCR everything is fine again but it is not a good solution to restart it!!!

I haven’t found any issues with other webpages.

Any ideas???

You found the solution? I have a similar problem.

You found the solution? I have a similar problem.