You have to unlock it for staking after it's fully synced (and after the 101 confirmations of your holdings)
Once you have 101+ confirmations, go to tools, open wallet configuration file and change it to the below, save it and then restart your wallet and then unlock it and then it will start staking in a min or two.
rpcuser=YOUR NAME (you can just make it up)
rpcpassword=YOUR PASSWORD (you can just make it up)
rpcallowip=127.0.0.1
staking=1
listen=1
server=1
daemon=1
logtimestamps=1
maxconnections=256
good post