Yesterday evening I asked a question in the main search bar and was provided with a quick answer.
This morning I still had the browser tab open, and I asked a follow-up question in the input below the original answer from yesterday.
I was taken to a "not found" page - the URL path ended in /null whereas I think that normally the final path section in the URL is a UUID.
When I reloaded the page (browser refresh) to re-ask the same question, the behaviour persisted.
I expected to be able to start a "conversation" based on my previous quick answer, and be taken to assistant.kagi.com where I would be given the option to save the conversation.
Otherwise, I would at least expect to be able to restart the process from scratch by refreshing the browser, since the original query was in the URL query string.