Harvest lockup is an innovative approach to ensuring that harvesting doesn’t occur too frequently so that large players (whales) can’t harvest and dump their rewards thereby negatively impacting the price for the rest of the pool.
It varies depending on the pair you’re providing liquidity for. In a hypothetical example, the GROVE–BNB pair has a harvest lock of 2 hours. Without that time, the rewards from staking cannot be harvested.
Your principle investment can be withdrawn from liquidity at any time but if it’s withdrawn before the harvest lockup period is over, it incurs a .5% fee.
You can check the harvest lockup on each farm card.