Why do gel pen liners dry out so quickly?

I mostly use gel pen eyeliners when I do my makeup.

But is it supposed to harden this quickly?

It wasn't like this before, but since the past year, I feel like it hardens particularly quickly.

It felt like it started to harden after about 2 to 3 weeks.

It felt like a waste to throw it away right away just because it had hardened, so I tried blowing on it to write and even rubbing it on paper.

However, once the liner starts to harden, it never feels the same as when it was new.

Is it normal for it to harden after about 2 to 3 weeks like this?

I usually keep the lid closed properly, too...

Is there a way to prevent it from hardening?