AsNoriuanswered grow question 3h ago Increase space between tie and plant, thats first.
Expose plant to better lightning, now she stretches a lot, missing it.
Mist top head 3-4 times daily, seeds were old and plant is struggling to drop shell, she is too stiff now.
Never try to open it yourself or rip it off, usually in such cases leaves are not formed yet, you risk to rip them or even all head. Give time. No stress, few days with misting and high humidity in grow area should do the trick.