Long-lasting Liquid Liner

I purchased this a couple of months ago at the Bay and it is definitely long lasting. The formula is great as it is not runny, dries quickly and I found that it didn't smudge as well. It is also easy to handle/use which is a must for me.

Unfortunately, since I've had it for a couple of months now when I placed the cap on it one time, the brushes of the pen started to separate so it ruined how precise the pen was. Did this happen to anyone else?

I still use it, in this condition but obviously it requires some finesse when applying it on my eyelids. I would like to repurchase but wanted to find out if anyone else experienced the same thing (brush separating) and if there's a way to fix it or avoid it happening again in the future?