Curious as to why. Haiku 4.5 has been far away from pareto frontier for a long time. Maybe you need to update your prompt for the newer model in your workflow.
It performs well in the domains we’ve implemented it. Cheap, fast, good enough, multimodal. Its a workhorse and it strikes a nice balance. I’m open to the suggestion that I’m just winging it here and happened to get lucky with a model whose training fit our usage, which is boringly unspecific.
Probably explained by implementation around a particular model, no? I suspect if you put similar effort in, you could get Haiku 5.5 to do what you want.