I sometimes get conflicted staking rewards, is it normal or a bug of wallet? Please advise.
What do you mean by "conflicted"?
It's failed transaction I got, lost a staking reward, ut not sure why it says -159.20 MEDIC
Status: conflicted
Date: 5/7/2018 09:10
Source: Generated
Debit: 0.00 MEDIC
To: MQzz5qjKeRY7BzodCiiv1h4JcXM2Hpfie8
Debit: -159.20 MEDIC
Net amount: -159.20 MEDIC
Transaction ID: 5a8dac594450d6395b2ddb8d4e1f8f830a11ec94b3e604ec55704d475f110ee4-000
Generated coins must mature 80 blocks before they can be spent. When you generated this block, it was broadcast to the network to be added to the block chain. If it fails to get into the chain, its state will change to "not accepted" and it won't be spendable. This may occasionally happen if another node generates a block within a few seconds of yours.