Every validator has the potential to earn a portion of the staking rewards in return for operational service.
By default, for a new validator, the commission rate is set to 100%.
This would result in all staking rewards being deposited to the validator vote account and no increase in the delegated stake size.
Set the commission on your validator as follows
# set the commission rate to 10% ~/Safecoin/target/release/safecoin vote-update-commission ~/ledger/validator-vote-account.json 10 ~/ledger/validator-identity.json
You can change the validator commission levels at any time.