For flights, Chase hasn't enabled NDC capability, which means that both AA and UA (as of sometime last year) have yanked many of their lower-priced fare options away. But Expedia, which has enabled NDC, has access to those fares.

I've been very disappointed with the Chase portal too after getting my Sapphire card last year. I'll probably end up cancelling it next year unless they give me a decent retention offer. Depending on what my 10% point bonus turns out to be, maybe I'll keep it for the travel insurance policy. But I'm not particularly enthused about the card overall, to be honest.