当我运行时sudo flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo，我没有得到任何响应，并且命令未完成。我可以在浏览器中打开 flathub.org，并且在终端中也可以看到它的 ping：
PING flathub.org (8.43.85.5) 56(84) bytes of data.
64 bytes from flathub.org (8.43.85.5): icmp_seq=1 ttl=49 time=289 ms
64 bytes from flathub.org (8.43.85.5): icmp_seq=2 ttl=49 time=313 ms
64 bytes from flathub.org (8.43.85.5): icmp_seq=3 ttl=49 time=235 ms
--- flathub.org ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2001ms
rtt min/avg/max/mdev = 234.656/279.186/313.462/32.979 ms
问题是什么？