400 error on stripe checkout

[simonv3]

{
  "error": {
    "code": "parameter_invalid_empty",
    "doc_url": "https://stripe.com/docs/error-codes/parameter-invalid-empty",
    "message": "You passed an empty string for 'line_items'. We assume empty values are an attempt to unset a parameter; however 'line_items' cannot be unset. You should remove 'line_items' from your request or supply a non-empty value.",
    "param": "line_items",
    "request_log_url": "https://dashboard.stripe.com/logs/req_2JgEQ6CGJ2Qxhh?t=1667023632",
    "type": "invalid_request_error"
  }
}

This is happening with quite a few requests. We've only had one report, but I'm seeing it every couple of days in the logs.