Zend certified PHP/Magento developer

Connection to website fails

I am trying to connect to a website. From my laptop, located in my WLAN, it doesn’t work:

joesse@laptop~> ping -c 1 www.ttrss.info
PING www.ttrss.info(vps-4c11fdd7.vps.ovh.net (2001:41d0:304:200::c2d)) 56 Datenbytes
64 Bytes von vps-4c11fdd7.vps.ovh.net (2001:41d0:304:200::c2d): icmp_seq=1 ttl=50 Zeit=25.1 ms

--- www.ttrss.info ping-Statistik ---
1 Pakete übertragen, 1 empfangen, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 25.141/25.141/25.141/0.000 ms

joesse@laptop~> curl -v https://www.ttrss.info
*   Trying 2001:41d0:304:200::c2d:443...
*   Trying 146.59.155.110:443...
* connect to 2001:41d0:304:200::c2d port 443 failed: Die Wartezeit für die Verbindung ist abgelaufen
* connect to 146.59.155.110 port 443 failed: Die Wartezeit für die Verbindung ist abgelaufen
* Failed to connect to www.ttrss.info port 443 after 131066 ms: Die Wartezeit für die Verbindung ist abgelaufen
* Closing connection 0
curl: (28) Failed to connect to www.ttrss.info port 443 after 131066 ms: Die Wartezeit für die Verbindung ist abgelaufen

which basically means “Timeout” for the ipv6-address, timeout for the ipv4 address, timeout for the host name. If I do the same on my mobile phone, located in the same WLAN, I get:

127|:/ $ ping -c 1 www.ttrss.info
PING www.ttrss.info (146.59.155.110) 56(84) bytes of data.
64 bytes from vps-4c11fdd7.vps.ovh.net (146.59.155.110): icmp_seq=1
 ttl=64 time=215 ms

--- www.ttrss.info ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 215.189/215.189/215.189/0.000 ms
:/ $ curl -v https://www.ttrss.info
*   Trying 146.59.155.110:443...
* TCP_NODELAY set
*   Trying 2001:41d0:304:200::c2d:443...
* TCP_NODELAY set
* Connected to www.ttrss.info (2001:41d0:304:200::c2d) port 443 (#0
)

and then messages about invalid certificates, but basically I am connected.

So I think my laptop is misconfigured. I am running openSUSE Leap 15.4, and I’d say that all other internet use works as expected. And I have no idea how to make this work.