Here how I setup this for OSS game engine I work on:
https://github.com/vcmi/VCMI.eu/
The widelands site seems to go directly to netcup in Germany. It is likely just a DDoS detector mistaking sudden interest as an attack.
https://docs.github.com/en/pages/configuring-a-custom-domain...
Here how I setup this for OSS game engine I work on:
https://github.com/vcmi/VCMI.eu/