ARM update fails with 2023-08-01 when setting updateChannel property

[dstarkowski]

Deploying Azure Cache for Redis instance with bicep template below. The initial deployment works as expected without any issues.

Running deployment again when resource already exists results with error:

"The unknown resource response code 'NotModified' is encountered."

Removing the line updateChannel: 'Stable' fixes the problem. Stable is the default either way. The problem only affects version 2023-08-01 (older versions don't have this property).

resource redis 'Microsoft.Cache/redis@2023-08-01' = {
  name: 'redis-${uniqueString(resourceGroup().id)}'
  location: resourceGroup().location
  properties: {
    sku: {
      name: 'Basic'
      family: 'C'
      capacity: 0
    }
    redisConfiguration: {
      'maxmemory-reserved': '30'
      'maxfragmentationmemory-reserved': '30'
      'maxmemory-delta': '30'
    }
    enableNonSslPort: false
    redisVersion: '6.0'
    publicNetworkAccess: 'Disabled'
    minimumTlsVersion: '1.2'
    updateChannel: 'Stable'
  }
}