Cannot access to facebook and only facebook?

[master lester]

Hi, I started to ahve this problem lately, sometimes my network (It happens in all computers) won't load facebook, I already checked the firewalls, turned off antivirus, checked the network, talked to my service provider and everything seems to be fine, but sometimes facebook won't load and only facebook, is pretty weird because I don;t have any website blocked and it only happens with facebook, I also tried just putting the ip address of facebook and the https and still is not working, sometimes in the afternoon works and sometimes in the morning, can somebody tell me if you had this problem before and how did you fix it, thank you.