Migrating UXP Plugin from v5.5.6 to v6.3.3 issue

Hello everyone. I have a strange issue, when updated my ps version. In short terms - i’m trying to connect to remote database using fetch function (which is used from UXP system). And getting the error, showing on screenshot below. I’ve tried to run this code with manifest v4 or manifest v5 with same results. So this is not a required permission case (because they appeared in manifest v5).
The code is below. Strange that on previous version of UXP all works fine.

request = request.then(
  () => fetch(url, {
    method: "post",
    credentials: "include",
    headers: {
      Accept: "application/json",
      "Content-Type": "application/json",
      "ftrack-api-key": this.apiKey,
      "ftrack-user": this.apiUser,
      "ftrack-Clienttoken": this.clientToken,
      "ftrack-pushtoken": pushToken
    body: this.encodeOperations(operations),
    signal: abortController && abortController.signal
request = request.catch((reason) => {
  logger.warn("Failed to perform request. ", reason);
  if (reason.name === "AbortError") {
    return Promise.resolve({
      exception: "AbortError",
      content: reason.message
  return Promise.resolve({
    exception: "NetworkError",
    content: reason.message

to developers:
i’ve found, that the problem was in this line, where the signal was undefinded.

I think you need try/catch for this case or handling undefined somehow. To pass throug and not stopping execution. In my case, i’ve just commented this line, and everything is working fine!