I'd love to know more about the setup here. I am aware of
https://bugzilla.mozilla.org/show_bug.cgi?id=1595046 which is for cases when someone rejects a Promise with a non-Error (and non-DOMException, I suspect) object. Is that what's going on here? Or could it be the thing described in
https://bugzilla.mozilla.org/show_bug.cgi?id=1595046#c5 with throwing a random non-Error object and the resulting console interaction?