High cost of Azure Storage Account File Share for "hot grs write operations"

Question

I am running a few sites in Azure App Service containers and I'm currently using path mapping to an AzureFiles resource.
This is used to share 10-15 small files between containers (read/write), totaling < 100Mb.

In the calculator the cost of this storage shows as £0.0396 per used GiB, the total size of the File Share has a quota of 1 GiB, however the fist month of billing has come to £26.93.

Drilling down to the cost, the major bulk is coming from "hot grs write operations" but I don't understand how this is possible, the pricing shows £0.1156 per 10,000 write operations, so to amass the £24.97 it would be 2.16 million write operations per month? That doesn't seem possible, have a mis-configured something?
The file store currently shows:
QUOTA
1 GiB
USAGE
19.3 MiB
TIER
Hot

Do I need to change to a different storage tier?

My storage account setup is below:

{
  "sku": {
    "name": "Standard_RAGRS",
    "tier": "Standard"
  },
  "kind": "StorageV2",
  "id": "/subscriptions/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxx/resourceGroups/[res group]/providers/Microsoft.Storage/storageAccounts/[storage name]",
  "name": "[storage name]",
  "type": "Microsoft.Storage/storageAccounts",
  "location": "uksouth",
  "tags": {},
  "properties": {
    "minimumTlsVersion": "TLS1_2",
    "allowBlobPublicAccess": true,
    "networkAcls": {
      "bypass": "AzureServices",
      "virtualNetworkRules": [
        {
          "id": "/subscriptions/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxx/resourceGroups/[res group]/providers/Microsoft.Network/virtualNetworks/[res group]-vpn/subnets/files",
          "action": "Allow",
          "state": "Succeeded"
        }
      ],
      "ipRules": [],
      "defaultAction": "Allow"
    },
    "supportsHttpsTrafficOnly": true,
    "encryption": {
      "services": {
        "file": {
          "enabled": true,
          "lastEnabledTime": "2020-10-06T15:35:36.8338261Z"
        },
        "blob": {
          "enabled": true,
          "lastEnabledTime": "2020-10-06T15:35:36.8338261Z"
        }
      },
      "keySource": "Microsoft.Storage"
    },
    "accessTier": "Hot",
    "provisioningState": "Succeeded",
    "creationTime": "2020-10-06T15:35:36.7713802Z",
    "primaryEndpoints": {
      "dfs": "https://[storage name].dfs.core.windows.net/",
      "web": "https://[storage name].z33.web.core.windows.net/",
      "blob": "https://[storage name].blob.core.windows.net/",
      "queue": "https://[storage name].queue.core.windows.net/",
      "table": "https://[storage name].table.core.windows.net/",
      "file": "https://[storage name].file.core.windows.net/"
    },
    "primaryLocation": "uksouth",
    "statusOfPrimary": "available",
    "secondaryLocation": "ukwest",
    "statusOfSecondary": "available",
    "secondaryEndpoints": {
      "dfs": "https://[storage name]-secondary.dfs.core.windows.net/",
      "web": "https://[storage name]-secondary.z33.web.core.windows.net/",
      "blob": "https://[storage name]-secondary.blob.core.windows.net/",
      "queue": "https://[storage name]-secondary.queue.core.windows.net/",
      "table": "https://[storage name]-secondary.table.core.windows.net/"
    }
  }
}

Answer 1

Please refer to the following on how to find the source of your write operations:
https://stackoverflow.com/questions/55808709/how-can-i-find-the-source-of-my-hot-lrs-write-operations-on-azure-storage-accoun

Hope this might help :)