KNC Unstaking Error

Good day.
Tried to unstake my KNC through BSC multiple times but failed. And the gas fee is even 0.4 BNB. When the metamask confirmation pops up, there’s a note “Transaction Error. Exception thrown in contract code.”
I click confirm then there’s a pop-up that says “Transaction was not mined within 50 blocks, please make sure your transaction was proper…”

Badly need your help withdrawing my KNC. Thank you!