- I had defined a custom assistant, along with a bang, to use the Qwen 3 32B model
- I used it many times
- At some point that model ceased to exist on Kagi; only the larger 235B models and the new Qwen Coder model are available anymore
- When I used my bang, it defaulted to using Claude-4. In fact, it replaced the model explicitly with Claude-4 in the definition of the custom assistant, see screenshot.

Obviously I cannot prove that this definition really did point to the Qwen 32B model before. The only way to reproduce it is to wait until one of the other models one has a custom assistant for, goes out of service.
I would expect the custom assistant definition to be changed to an "undefined" model, and error to be shown when I try to use the custom assistant by bang or by selecting it from the drop down.
I imagine some users might not notice that a different (and much more expensive) model is used. I only noticed because I am in a habit of always checking the token number and cost info at the end of the assistant response.