Hi @ovizii, welcome to the community and glad to hear you figured this out, thanks so much for confirming!
I quickly tested this myself, but would also run into this problem only when using the test link from Pushbullet. The authentication process initiated by n8n was working fine and without error messages:
I think there is not much we can do about the actual error from our end, since the test link from your original message is generated by Pushbullet. I will add a note to our respective though when I have a bit of time over the next days so future users are aware of this.