Error: {type: 'start-method-error', stage: 'unknown', error: Response, totalDuration: 1139, timestamp: '2025-07-19T15:47:11.837Z', …} it works before until now, here's my start function

vapi.start(undefined, undefined, undefined, process.env.NEXT_PUBLIC_VAPI_WORKFLOW_ID!, {
          variableValues: {
            username: userName,
            userid: userId,
          },
        });

@User workflow id: 18c16662-ac96-4c0f-9944-954205cc84f5 it works in development, but doesn't in production (all worked well before).