Windows Push Notification Services: 406 Not Acceptable

[collimarco]

We see a few delivery errors (Webpush::ResponseError) from our logs for the Windows Push Notification Services (WNS):

host: wns2-sg2p.notify.windows.com, #<Net::HTTPNotAcceptable 406 Not Acceptable readbody=true>
body:

All the browsers that we have tested on Windows 11 (including Edge - v105) work properly. The notifications are delivered successfully and no exception is raised.

This is probably some misconfiguration in a specific server of WNS, some transient errors on WNS or some strange browser version that doesn't work properly (e.g. returning wrong push subscriptions that create an anomalous response from WNS).

In any case I open this issue in case anyone can reproduce this problem or has more information.

[collimarco]

Probably this is the root cause: https://github.com/zaru/webpush/pull/103