The use of a Virtual Private Network (VPN), a browser plugin or another program might be related to the current blocking. You might try uninstalling the VPN from your computer or network and see if that makes a difference.
Some VPNs send traffic that violates the law or websites' terms of service. When the abuse to Qwant's network stops, we automatically stop blocking the IP that were sending the bad traffic.
If you are unsure about a malicious usage of your network, this website (english only) may be a good reference to start with.