Marketing lied, gently :) "Instant" describes the CONVENIENCE - it mixes straight into flour with no blooming step - not the rising speed. Your two hours is a completely healthy, normal fermentation.
The actual expectations: at the 27-35°C sweet spot, an hour or two to double is standard. Cooler rooms stretch it further, and that's fine - slower fermentation actually builds better flavour. Nothing about the word instant exempts the yeast from biology.
And the readiness verdict stays with the dough, never the clock or the packet: doubled, jiggles when nudged, a gentle dent springs back slowly. Your yeast is alive, well, and working exactly on schedule - the schedule just wasn't the one the label implied 🙂