@mattj@mastodon.technology @0 it's technical issues where Apple keeps breaking things in ways that notifications from third party servers don't work well. The XMPP devs (Tigase/Siskin, Monal, prosody, etc) keep fixing them and then Apple makes a change to break it again.
@mattj@mastodon.technology @0 also, as much as I dislike the way that Moxie handles Signal (aggressively against actual FOSS or connecting with any forked client, etc), at least the source is available and it's not run by Facebook. WhatsApp is worse in every way.