I use Firefox 134.0.2 (64-bit) on Ubuntu 24.04. Some (not all) web sites show up only after a delay of '''exactly''' 30 seconds. The attached screenshot shows that this delay is due to DNS resolution. This behavior is reproducible by simply closing Firefox, opening it again and entering the same web site once more. Once this initial delay of 30 seconds for DNS resolving has passed the web site can be browsed normally. Using Google Chrome, Opera or even the Tor Browser on the same system works without any significant delay. Also a DNS lookup from the console returns data almost immediately. As the delay is always exactly 30 seconds this looks like some DNS resolver timeout only showing up when using Firefox. Neither starting Firefox in ''Troubleshoot Mode'' nor (as often suggested) disabling IPV6 for DNS by setting ''network.dns.disableIPv6'' to ''true'' did help. Any idea how to fix this 30 seconds delay? Many thanks for any help, Felix