webhook keeps firing

webhook keeps firing

My webhook keeps firing every 10 minutes, instead of just once.

It is configured with a workflow action on create/edit that checks the existence of a (custom) field, and fires if it is true.

The webhook service returns an empty response with status 200 OK.

It completes in 10 seconds or less -- btw, what is the timeout on webhooks?

It has fired 15 times now in the 2.5 hours since I "tested" it by saving a record, firing every 10 minutes with the same data.

There is nothing listed in the errors tab.