That sort of message can be due to a variety of reasons but one of them is bots crawling over the website to scrape information off.
The IPFire git repo web browser site has this problem periodically also.
The effect from so much scraping by the bots is that it acts like a DoS attack and stops proper users from being to access it.
Try again tomorrow. The bot scraping usually only occurs for a certain amount of time.
If it is still occurring tomorrow then it could be due to a problem with their website server, it has either crashed or locked up for some reason. That requires the owner to restart there website infrastructure.
Tried again just now and it’s still the same. On one occasion a few weeks ago I whitelisted an IP address I found for the site and it worked. On a Windows 11 box it all works https://www.arduino.cc/en/software and downloaded arduino-ide_2.3.6_Linux_64bit.zip. I’ll scp it to my openSUSE Tumbleweed box tomorrow and give it a try.
Found something interesting this morning. No problems with the Windows 11 and openSUSE tumbleweed boxes downstairs connected only with Wifi. Upstairs, fails when connected with both Ethernet and Wifi. “ifconfig enp8s0 down” works fine. “ifconfig enp8s0 up” and it fails.
Very weird — upstairs Fedora 42 box connected with both Ethernet and Wifi – no problems. BananaPi-F3 running bianbu-3.0 connected with both Wifi and Ethernet - no problems, so it seems the problem is related only with openSUSE.
I actually found Suricata to be the reason for similar problems in the past. Mostly after a core update there are some new strict IPS rules that I need to comment out to avoid the aforementioned DNS problems. To the OP: read the IPS logs, you might find a pointer to some rule that blocked DNS from resolving a certain domain name.
Call it coincidence but today I had the same problems as the OP but with the domain azurewebsites.net being blocked by Suricata resulting in DNS problems with most of my work-related network connections. I had to comment out the rule accordingly which solved the problem.
Sometimes such problems happen, maybe after a nightly update of the “Emergingthreats.net Community Rules“ or after a core update. I need to monitor the problem more closely.