Error: project ID request rate exceeded

Querying some wallets in a loop, I get this error no matter what I do, tried to sleep 5 seconds between each call, to no avail… My free account should have 100k requests per day. I used only 2k… is there some kind of per hour limit that I should know about?
or else what should I do?

Error: project ID request rate exceeded
    at /app/node_modules/truffle-hdwallet-provider/dist/index.js:15:632675
    at t.i.onreadystatechange (/app/node_modules/truffle-hdwallet-provider/dist/index.js:15:748948)
    at t.e.dispatchEvent (/app/node_modules/truffle-hdwallet-provider/dist/index.js:1:142373)
    at t._setReadyState (/app/node_modules/truffle-hdwallet-provider/dist/index.js:15:753708)
    at t._onHttpResponseEnd (/app/node_modules/truffle-hdwallet-provider/dist/index.js:15:756793)
    at IncomingMessage.<anonymous> (/app/node_modules/truffle-hdwallet-provider/dist/index.js:15:756051)
    at IncomingMessage.emit (events.js:327:22)
    at endReadableNT (_stream_readable.js:1220:12)
    at processTicksAndRejections (internal/process/task_queues.js:84:21)

Hey @shaharsol - welcome to the Infura community! Reach out to to help you with this. Sometimes it happens when there are bursts of requests.