Kusto query still hit old memory budget limit after increase?

Question

I still hits the old maxmemoryconsumptionperiterator limit even after increasing using .alter-merge workload_group default command:

'summarize' operator has exceeded the memory budget (32212254720) during evaluation. Results may be incorrect or incomplete (E_RUNAWAY_QUERY; see https://aka.ms/kustoquerylimits).

.show workload_groups shows the correct updated value:

{
  "RequestLimitsPolicy": {
    "DataScope": {
      "IsRelaxable": true,
      "Value": "All"
    },
    "MaxMemoryPerQueryPerNode": {
      "IsRelaxable": true,
      "Value": 68718888960
    },
    "MaxMemoryPerIterator": {
      "IsRelaxable": true,
      "Value": 68718888960
    },
    "MaxFanoutThreadsPercentage": {
      "IsRelaxable": true,
      "Value": 100
    },
    "MaxFanoutNodesPercentage": {
      "IsRelaxable": true,
      "Value": 100
    },
    "MaxResultRecords": {
      "IsRelaxable": true,
      "Value": 9223372036854775807
    },
    "MaxResultBytes": {
      "IsRelaxable": true,
      "Value": 9223372036854775807
    },
    "MaxExecutionTime": {
      "IsRelaxable": true,
      "Value": "00:04:00"
    }
  },
  "RequestRateLimitPolicies": [
    {
      "IsEnabled": true,
      "Scope": "WorkloadGroup",
      "LimitKind": "ConcurrentRequests",
      "Properties": {
        "MaxConcurrentRequests": 160
      }
    }
  ],
  "RequestRateLimitsEnforcementPolicy": {
    "QueriesEnforcementLevel": "QueryHead",
    "CommandsEnforcementLevel": "Database"
  }
}

Adding set maxmemoryconsumptionperiterator=68718888960; in front of the query also has no effect.

What else am I missing?