In this particular case, 3,560 HYDRA out of the total 59,319 is unavailable because the UTXOs behind this amount had become block producer(s) within the last 500 blocks and are still locked.The remaining 55,759 HYDRA are actively competing in the staking. The small lockdown % is a sign the UTXOs are probably sufficiently optimized since if it was a single UTXO, the whole amount would show as "staking" and therefore unavailable.