Originally Posted by The Narrator

Is it just you, or has the Hufflepuff Common Room entrance seemed a little sluggish recently, perhaps taking a few seconds longer than usual to respond to the passcode it's been given?

No. Not just you. All at once, the barrels have become unquestionably unreliable. At times, it works fine, perfect working order, while at other times it will leave you stuck outside the common room for ten or fifteen minutes at a time before suddenly springing into action. Occasionally even the correct series of taps on the barrels by a Hufflepuff will soak an unsuspecting student with vinegar. Whatever enchantments maintain the entrance are undeniably on the blink.

If you're lucky, someone might just happen to force the barrels open from the inside, where a passcode isn't needed, otherwise you'll just have to be patient.