What was the consistency of thge product when you applied it?
Nice & smooth or a litle stiff?
Did it have the strong "vinegar" smell characteristic of fresh product?
If not it might have been too old, I'm pretty sure the unopened shelf
life is way less than 2 years.
If you have some left squirt a little out onto a piece of paper or wood
& see if it cures. If this test squirt cures your installation will
Silicones are moisture cures, they get the moisture from the air. If
they are already paritally cured (old) when applied the cure process
really slows down.
If you're not in a hurry I'd give it at least a week., maybe two