Aave V2 Ethereum - reserve.totalLiquidityAsCollateral appears to be overstated in some markets

Describe the bug
In the Aave V2 Ethereum subgraph, the reserve.totalLiquidityAsCollateral return value appears to be incorrect for some markets. It returns a value which is greater than the reserve.totalLiquidity for that market.

Incorrect markets include stETH (below), USDC and Frax. This list isn't exhaustive - there may be more.

To Reproduce
Query:

query MyQuery {
  reserve(
    id: "0xae7ab96520de3a18e5e111b5eaab095312d7fe840xb53c1a33016b2dc2ff3653530bff1848a515c8c5"
    block: {number: 16501589}
  ) {
    totalLiquidity
    totalLiquidityAsCollateral
  }
}

Response:

{
  "data": {
    "reserve": {
      "totalLiquidity": "899695114262182690563902",
      "totalLiquidityAsCollateral": "1070577614223086581220014"
    }
  }
}

Expected behavior
The totalLiquidityAsCollateral value should be less than or equal to the totalLiquidity value.

Start by reproducing the supplied GraphQL query for the stETH reserve at block 16501589, then trace the subgraph implementation that computes reserve.totalLiquidity and reserve.totalLiquidityAsCollateral. Compare the collateral aggregation for stETH, USDC, and Frax with the reported values. Done means totalLiquidityAsCollateral no longer exceeds totalLiquidity for the affected markets.