To success spend of OP_CLTV, following requirements must meet:

• nLocktime is required
• if nLockTime typed datetime detected, then value must satisfy < chain's MTP.
• if nLockTime typed block height detected, then value must satisfy < chain's block height + 1.
• if OP_CLTV detected, then its time parameter must satisfy >= nLockTime.
• At least one input's nSequence must set lower than max value #FFFFFFFF to enable nLockTime.