Taking a wild guess here, maybe the Internet Service Provider is restricting bandwidth for various IPs because they downloading too much, and your connection to the CMF servers got caught in the net.
Another possible reason is the DNS server. If you know how to do this, then try changing the DNS server for your modem. I like using the 1.1.1.1 or the 8.8.8.8 with the former being a fast Russian one and the latter being Google.
The DNS server my ISP wanted me to use was pretty bad, it was kind of slow, sites would not load, finally I had enough and tried different DNS servers, those two mentioned above are the most reliable I feel.
(Logging into your modem is not that hard. Just Google what is the intranet link to the modem brand, mine is 192.168.1.1 and the password username should be admin admin that lets you in and you can go change the DNS.)
