This incident is resolved. Between 13:02 and 16:50 UTC, an issue on our side caused some webhooks to be sent with an invalid signature, so endpoints that verify signatures rejected them. This mainly affected webhooks for data requested through the API, such as historical data requests, and some deliveries were delayed as a result. Rejected webhooks are being retried automatically with a valid signature and should arrive over the next few hours. If you temporarily disabled signature verification, you can turn it back on. No other action is needed.
Investigating · UTC
We are investigating webhook deliveries failing signature verification.