`/miners` hashrate differs from the hashrate shown in `/miners/address`
**Describe the bug**
I'm working with a Litecoin clone called defcoin. 

The overall mining stats do not match the individual performance:

```
root@defcoin-miningcore:~/miningcore# curl localhost:4000/api/pools/dfc1/miners
[
  {
    "miner": "D7VcZVYqaoLdJppgp9AsVRhmt9aWK9z4uW",
    "hashrate": 2649034,
    "sharesPerSecond": 0.053
  },
  {
    "miner": "DMTwnxXWMrdaU7USXRxekgT1y6TroC67zh",
    "hashrate": 1378949,
    "sharesPerSecond": 0.041
  }
]


root@defcoin-miningcore:~/miningcore# curl localhost:4000/api/pools/dfc1/miners/D7VcZVYqaoLdJppgp9AsVRhmt9aWK9z4uW
{
  "pendingShares": 0.3870845676189348,
  "pendingBalance": 0,
  "totalPaid": 0,
  "todayPaid": 0,
  "lastPayment": null,
  "lastPaymentLink": null,
  "performance": {
    "created": "2021-09-22T04:57:41.629893",
    "workers": {
      "": {
        "hashrate": 0,
        "sharesPerSecond": 0
      }
    }
  },
  "performanceSamples": []
}


root@defcoin-miningcore:~/miningcore# curl localhost:4000/api/pools/dfc1/miners/DMTwnxXWMrdaU7USXRxekgT1y6TroC67zh
{
  "pendingShares": 0.15760338578886043,
  "pendingBalance": 0,
  "totalPaid": 0,
  "todayPaid": 0,
  "lastPayment": null,
  "lastPaymentLink": null,
  "performance": {
    "created": "2021-09-22T05:03:41.667311",
    "workers": {
      "": {
        "hashrate": 681647,
        "sharesPerSecond": 0.107
      }
    }
  },
  "performanceSamples": []
  ```
I went back to miningcore-47 and didn't seem to have this issue.

Any clue what's going on here? It seems to be a bug to me, but it could also be inexperience. 