It may be due to their chat interface than in the model or their system prompt, as kagi's r1 answers it with no problems. Or maybe it is because of adding the web results.

https://kagi.com/assistant/98679e9e-f164-4552-84c4-ed984f570...

edit: it is due to adding the web results or sth about searching the internet vs answering on its own, as without internet access it refuses to answer

https://kagi.com/assistant/3ef6d837-98d5-4fd0-b01f-397c83af3...

edit2: to be fair, if you do not call it a "massacre" (but eg an "incident") it does answer even without internet access (not perfect but still talks of casualties etc).

https://kagi.com/assistant/ad402554-e23d-46bb-bd3f-770dd22af...