Everyone is censoring models now with anything remotely resembling cyber or bio. I already have problems with my research in mathematical epidemiology because of that - both Sol and Fable simply refuse. They keep pushing people towards Chinese models that can be decensored.
Supposedly Fable 5.1 is better, but I haven't tried it yet. I've run into the same thing with mundane work that is barely bio/cyber adjacent. Re: Chinese models, even if the model itself isn't censored, some of the big model providers have guardrails now that you can't exceed, which somewhat defeats the purpose.
And yes, Fable 5.1 has the same refusal rate, and significantly nerfed reasoning.