Incorrect path payment response from Horizon

[Alex0007]

Strict send request:

source_asset_type: credit_alphanum4
source_asset_code: USDC
source_asset_issuer: GA5ZSEJYB37JRC5AVCIA5MOP4RHTM335X2KGX3IHOJAPP5RE34K4KZVN
source_amount: 10
destination_assets: USDT:GCQTGZQQ5G4PTM2GL7CDIFKUBIPEC52BROAQIAPW53XBRJVN6ZJVTG6V

Response

{
  "_embedded": {
    "records": [
      {
        "source_asset_type": "credit_alphanum4",
        "source_asset_code": "USDC",
        "source_asset_issuer": "GA5ZSEJYB37JRC5AVCIA5MOP4RHTM335X2KGX3IHOJAPP5RE34K4KZVN",
        "source_amount": "10.0000000",
        "destination_asset_type": "credit_alphanum4",
        "destination_asset_code": "USDT",
        "destination_asset_issuer": "GCQTGZQQ5G4PTM2GL7CDIFKUBIPEC52BROAQIAPW53XBRJVN6ZJVTG6V",
        "destination_amount": "10.0044350",
        "path": []
      }
    ]
  }
}

While orderbook looks like this:

Is this a bug or a measure to fight arbitrage bots?

[bartekn]

Do you still experience this issue? There were some ingestion delays in the order book graph that /paths is using to find offers.

[marcinx]

For what it's worth, we have also been seeing op_too_few_offers situations recently, which basically never occurred in the past. Unfortunately I cannot provide more detail without digging deep into the logs but basically want to confirm that we have seen similar situations. op_too_few_offers was particularly frequent when we increased our MAX_PATH_LENGTH from 3 to 4.

[marcinx]

PS: We have also seen a noticeable spike in op_under_dest_min for strict send payments on smallish amounts where it is unlikely that the liquidity changed significantly from one ledger to another. Unfortunately I also don't have logs at hand for these txs but it almost seems like there might be something going on. Maybe related to the ingestion delays mentioned by Bartek. We don't seem to have any issues with strict receive payments.