I have also updated Pythörhead to be able to handle the new authentication (as well as the old), so if you're running a bot, make sure to update your Pythörhead dependencies.
Now is also a good time that you can support the running of this server. If you just want to support this instance, please use Ko-fi and you can get a custom emoji here. If you want to support my general development efforts as well (Lemmy, Pythorhead, Fediseer, Tagginator etc) feel free to use my liberapay
I am not entirely sure if it's something to do with 0.19, but my home instance, lemmy.sdf.org is also having issues with outgoing federation since upgrading to 0.19.x, although it's currently still just on 0.19.0-rc.13. That's also why I am writing this from this account instead.