Opus 5.5 medium effort tells me there are 30 rs in that string. Did you change the effort level or something? Also Opus 5.5 isn't a frontier model. Anthropic's frontier model is Mythos/Fable.
You're also splittin hairs if you argue Opus 5.5 isnt "frontier".
https://artificialanalysis.ai/models
Artificial Analysis considers Opus 5.5 to be the best current model, yes better than Fable.