We are experiencing an issue with Supabase table webhooks where custom headers disappear after saving, causing triggers to fail.
Observed behavior:
After saving the webhook, the dashboard shows no custom headers.
Attempts to re-add the header sometimes persist temporarily but then disappear again.
Impact:
The webhook handler rejects the request without the secret → 401.
Because Supabase triggers run inside the insert transaction, the insert fails, rolling back any record creation.
Other webhooks (on the same table/event) with headers work fine, indicating this is specific to this webhook instance.
Attempts to troubleshoot:
Replacing the secret with a shorter, simpler string temporarily restored functionality.
Even after this, the headers eventually disappear.
Confirmed that inserts work with the webhook disabled, confirming the problem is header persistence.
Deleting & recreating the webhook worked temporarily