I just set up an Argon, with nothing connected but power, in a Console product with the above webhook and code on OS2.0.1, and it fails in the same way. [edit: changed D22 to D6 in the code]
Loosing web hook reception was originally discovered happening in field test units without a reset. And remotely inducing a system.reset() did not restore it, but uploading slightly modified code did restore web hook reception.