Did you cool your beer soon after flame-out? Perhaps with a hot lag-time, the additions were shifted a bit further back, driving off more of the aromas? This can be an issue if you no-chill.

An easy fix would be to add some cascade directly to the fermenter, leave for 3 days, then bottle. This gives lots of hop aroma as primary fermentation is finished (so delicate aromas are not being driven off with the excess CO2), and the beer is a relatively hostile environment to any microorganisms on the hops (high alcohol, very low O2, low pH). You might be able to leave the hops in for longer, but some types can give "grassy" flavours if left in for too long. So I'm hesitant to recommend "3-7 days" in case you decided to use Saaz (for example).

Of course if you normally put your beer in a keg, wait until it's finished, then use a hop-sock or tea-infuser full of hops directly in the keg.

Was the sample you tasted very very cold? Cold temperatures diminish the body's ability to perceive flavours.

I've never found carbonation effects the hop aroma in a hugely significant way.

An easy fix would be to add some cascade directly to the fermenter, leave for 3 days, then bottle. This gives lots of hop aroma as primary fermentation is finished (so delicate aromas are not being driven off with the excess CO2), and the beer is a relatively hostile environment to any microorganisms on the hops (high alcohol, very low O2, low pH). You might be able to leave the hops in for longer, but some types can give "grassy" flavours if left in for too long. So I'm hesitant to recommend "3-7 days" in case you decided to use Saaz (for example).

Of course if you normally put your beer in a keg, wait until it's finished, then use a hop-sock or tea-infuser full of hops directly in the keg.