Later I learned that the reason was "phishing". All the content my website had was a JPEG of a cow, contemplating the choice between AMD and NVIDIA GPUs.
Honestly I don't even know whom to hate more, the registrar or the NVIDIA. I guess next time I should use .ru or .su, which have their own issues, but at least the NVIDIA corporation doesn't hold them by the balls.
Perhaps a name like "crowdsourced-nvidia-bugs.tryauuum.sh" with a header that says "Not directly affiliated with Nvidia" and links to a FAQ would be less likely to get the attention of the registrar.